Thunder Road Bikes
Kawasaki 750 H2 Special
“The Widow Maker” Plus Some!
The Finished bike!
Well I purchased the bike last summer (2007). I bought the best example that I could afford. These bikes are quite rare, and some parts even rarer. so I figured it would be probably less expensive in the long run. In the pictures it looks better than it really is, although its all there. It still needs work to be done. From what I understand, this bike came over to the UK from the States about 17 years ago. It was restored then left unregistered for 16 years. A bit of a waste I think, but never mind. Anyway, the 16 years have taken their toll. The wheels are in need of rebuilding, especially the rear one, as the hub and spokes are just grotty. I will be getting the hubs powder coated and I will be rebuilding the wheels with new chrome rims and stainless steel spokes. Not original equipment I know, but it's never going to be a concourse restoration, more of a total rebuild and hand finished. In other words it will be nicer than when it left the factory in Japan in 1972/3.
I am guessing that the mileage on the clock is correct at 7500 miles, as the bike still has the original Bridgestone rear tyre, NOBODY who rode bikes on Bridgestone's in the early 1970's would have fitted a replacement Bridgestone. A Dunlop TT100 or Avon Roadrunner perhaps, but not one of those 70's Bridgestone's. How times have changed, I now have Bridgestone Battleaxe tyres on my Yamaha Exup and can't rate them highly enough.
Exactly as I got it
The horrid rear wheel can be seen here!
Well here is the next chapter, Having removed the rear wheel and measuring the offset, I took an angle grinder to the spokes. This is the quickest way to remove the wheel hub. I removed all the wheel bearings and washed out the grease that had been there for about 35 years. It had turned quite hard. But having swilled petrol through them for about 30 mins, it all came out. A quick drop of light oil was added before I spun them with my fingers. All appeared to be sound, I then looked at the bearing surface very carefully for any signs of pitting. The bearings were good and could be reused.
I then took the brake drum, brake back plate and sprocket carrier to my local powder coater. I know a lot of you that restore bikes, polish the brake drum and leave it bare polished alloy. I like this look, but I am a little concerned about putting stainless steel spokes into a bare alloy brake drum, I learned a while ago that stainless and alloy have a chemical reaction when placed in contact with each other. I usually get away with this when using stainless engine casing Allen keys, bolts etc. by coating them with plenty of copperslip grease to keep a barrier between the two metals. Unfortunately you can't do this with spokes as the grease would be visible. So I opted to keep them apart with the powder coating, plus as I intend to ride this bike, rather than just look at it. Powder coating in such hard to keep clean areas is a bonus.
When I picked up the parts from the powder coaters, I rushed home to replace the bearings that had been repacked with fresh grease so that I could take the wheel to be rebuilt with a new British chrome rim and stainless spokes. It took a couple of weeks for the wheel to be rebuilt. I went to collect it, it looked great. Purely by chance I measured the offset; my newly rebuilt wheel was about 1/4" out. I could not believe it, I had given the guy all the measurements, but It was still out. With disgust I took my wheel to another wheel building shop to be put right. I know I could have gone back to the original guy, but I just thought, NO! he had his chance and he screwed it up, so I will never go there again. With my wheel now put right, I just thought, how glad I was that I checked it. The H2 handle's badly enough with the wheels running true, god knows what it would have been like with the wheels out of line.
The Brake drum looks grey in the pictures, but it is actually silver.
Although the engine seemed to run ok when I got the bike, I always like to strip the motor to look for any problems, or worse still, bodges that previous owners have made. The last place to find out a previous owner forgot to tighten something is while riding down a motorway at 70 MPH.
I also know through past restorations that I have done, that leaving an engine unused for years does it no good at all, the crank seals harden, there could be pitting on the bearing surfaces etc. etc. Perhaps it's just me, but I really like to know what's in there BEFORE I ride it.
Removing the engine from the H2 was a very easy job, having restored mainly Suzuki GT750's for a few years, the H2 engine is just so light in comparison this engine is easily removed by one man.
Pulling the engine apart was also very easy, the heads came straight off, and so did the barrels. However I am guessing these barrels have been off before as I know they can be a pig to remove if the studs have rusted, plus my outer two barrels have broken fins where some previous owner has hit them with something in an attempt to remove them, fortunately the fins can easily be repaired. After removing the barrels I measured the bores, standard size bore with no visible wear. another indication that the bike as only done 7500 miles from new. A close inspection of the bore surface reveals pitting. Like I said leaving an engine unused for years does them no good. Cast iron bores will get covered in surface rust over a period of time, putting a drop of oil down the bores may help you get it running, but when the piston has removed the surface rust, there will be pitting in the surface. It's not always necessary to rebore the cylinder, it will work fine unless the pitting is really bad. But pitting on the cylinder walls usually means pitting elsewhere. Pitting on a bearing surface is much more serious, I have seen a Suzuki GT750, whose owner started it up after it had stood for about ten years, blow it's big end bearing in less than 500 miles.
I stripped the rest of the motor, it showed no signs of ever been apart before. You can nearly always tell if you look for the tell-tale signs, reused tab washers etc. But no, nothing on this motor. It all came apart very easily apart from separating the two crankcase halves, they were a pig to separate. I had to keep checking to see if I had missed a nut or something, A tiny gap had appeared but they just did not want to come apart. It took me a good 20 minutes with a soft hammer to separate them. When they eventually came apart it all came clear to me, Kawasaki actually use some sort of rubbery glue on the main bearings to stop them from rotating in the crankcases, so the cases were in effect glued together. I must say, it's a bit of a cheap idea, the Suzuki GT750 uses a much better method, with a small pin to locate the bearings on and stop the rotating. Things were now looking both good and bad. Good, the gearbox looks brand new, this engine has only done the 7500 miles on the clock. Bad, there is a lot of side to side movement at the little end of the con-rods. On a Suzuki GT750 anything more than about 2 to 3 mm is bad, and your crank needs help, my Kawasaki had a good 5 mm of side to side movement on all it's rods. I think the bearings must have been covered with surface rust, and pitting, so when the engine was started, the bearings just wear out so quickly. Glad I didn't ride it now, I did say I like to know what's in there before I blast it up the road. I get the feeling that with a good blast and 8000 revs it would have gone big style.
I sent my crank away to Chris Ritchie at Richie engineering for his opinion. I knew what he was going to say but I wanted to hear it from him. He phoned me to say that two of the rods were on the limit and the other was out of tolerance. No shock there, it's what I had expected. Chris said he wasn't happy about the rods in general, and didn't want to put it back together without some new parts. I agreed with him, if you are going to the trouble of rebuilding an engine, you just don't want to have to do it again in six months. I asked Chris to give it anything it needed. In the meantime, I was looking at the rest of the engine. Firstly I like to have the crank cases powder coated, they look good when done, but are also very easy to keep clean, a quick blast with the jet wash and they come up like new. So off they went to be coated silver. At this point I got to know a guy in the states called Joe, or Smoking Joe. I actually saw his video on You Tube (the one below) and contacted him. I was interested in how much work had gone into his H2 to make it run the quarter in the low ten's. "Very Little" was his answer. This made me even more interested. I have tuned quite a few Suzuki GT750's for myself and for others, but my intention with this bike was to keep it standard. That didn't last for long. The thought of a Kawasaki H2 that could do the quarter mile in 10 teens was just too much for me. I then decided that my Kawasaki H2 was destined for better things. I threw all sanity out of the window and ported the barrels to the same spec as Joe's. This H2 is going to be quick, very quick. I will be using it for limited road use and a bit of drag racing just for fun. Who knows what it will do to the gallon when it's finished, but hey who cares! It's a fun bike not a tourer. I just think to myself sometimes, I must be mad, why make a bike that has a reputation for bad handling, and a frame that could barely hold the bike together with it's standard engine and tune it for more power? Well, I guess my answer is, "You only live once" and "I will live more in ten minutes riding this bike than most people do in a lifetime"
Crankcases back from the powder coaters!
Lock, Stock, and Three Smoking Barrels
It's amazing how these barrels actually looked ok and clean on the bike, but look really grotty when removed. Ported, and ready to be sent to Chris Ritchie for the broken fins to be repaired. You can just about see the damage on the front of the two outer barrels. Two great lumps missing! They will then be rebored up to the first oversize, and sent off to be vapour basted.
My Crankshaft arrived back from Chris Ritchie, What a lovely job he has done! New rods, all new bearings and seals. A work of art!
I always clean up the threads before I attempt to put the cases together. You will usually find at least one which doesn't want to play ball. It's better to sort it now than when you are trying to bolt it all together. With my powder coated cases, there was a lot of silver coating on the treads. Obviously this all needs to be cleaned off now or you will have a lot of trouble when you cannot get your nuts to start on the treads. I just run a die from my tap and die set up and down the treads a couple of times.
To stop the main bearings from rotating in the cases (as there is no peg as there is on a Suzuki GT750) I intended using a bearing lock fluid. However you must clean ALL grease from the cases and bearing for the bearing lock to work. I use carb cleaner for this purpose, It is a fantastic cleaner of parts. Be careful when using it near to painted surfaces however as it takes the paint off.
I have always used Threebond Liquid gasket for sealing my crankcases back together, It' a nice gray colour too, so any surplus that squeezes out of the gap is barely visible.
Crankshaft back in, and cases bolted back together. I used stainless steel nuts with plenty of Copperslip
I lifted the crankcases back into the frame. Its' much easier and lighter to man-handle when it's in this stripped down state.
Well, I have just received an email from a guy who asked how things were going with my bike. SLOWLY! was the answer. Well I have had a few up's and downs to say the least. The barrels that are in the picture above were posted out to Chris for a little welding on a couple of broken fins. I received a phone call from Chris about a week after I had sent them. BAD NEWS! despite having wrapped the barrels in about 4 inch of padding called bubble wrap. One of my barrels sustained serious damage while in transit. A huge piece of cast iron liner had broken off. This has just about scrapped one of my barrels. The only answer was to try and find a second hand barrel or fit a new liner. Well, while speaking to Chris on the phone a new plan was hatched. If you are fitting one liner, you may as well fit three yes? Well liners these days are made from much better materials than the section of cast iron fall pipe pushed into cylinders 40 years ago. We now have modern materials, better technology, so why not bring at least a part of my 36 year old engine into the 21st century? Chris came to the rescue once again, Chris could locate, supply and fit my barrels with spun cast steel liners, Wow. not sure what it means but it sure sounds good ha ha. They could also have bridged intake ports which the Kawasaki doesn't have as standard. This effectively means that you can run a much wider intake port and still have plenty of support for the piston. This is a good idea for a few reasons. Firstly, if you tune a straight forward piston ported two stroke engine you generally have to widen the intake port and/or lower the bottom of it to increase the intake timing. If you can get the power you are looking for by just widening the port this is definitely the way to go. as widening doesn't have too much effect on low down power. If you have to lower the bottom of the port to increase port timing you will loose bottom end power unless of course you have reed valves (see plan "B" below). Another very good reason for a bridged port is the extra support for the piston. Old two strokes like these especially large capacity ones have huge holes for the exhaust and inlet ports in the liner. big holes mean less liner to actually hold the piston. Less liner means "Rattle" or "Piston Slap" because 1. there is not much liner actually holding the piston 2. because there is not much contact between the piston and the liner heat transfer from the piston to the liner/alloy barrel is not too good. To compensate for this poor heat transfer you need larger running clearances between the piston and liner to allow the piston to expand without seizing. What do large clearances cause? you may have guessed this, even more "rattle" or engine noise. If you have heard a Kawasaki triple or any other air cooled two stoke running you will know exactly what I mean. When I first got my bike and started it I could not believe the amount of mechanical racket going on. I honestly believe the engine noise is louder than the noise from the exhaust pipes. I thought it was just mine, but no, they are all like that. You have to remember that you have a bike from nearly 40 years ago, emissions and exhaust noise wasn't the issue that it is now. I think that a lot of people fitted this bike with loud expansion chambers so they could hide the din coming from the motor. As Kawasaki said in their advertising "Let the good times roll".
My spun cast steel liner? with bridged intake port.
While in talks with Chris, a new plan was formulated, (like they do ha ha ) My bike is now heading down a different route altogether. You see, Chris drag races one of his H2's and certainly knows how to improve them over standard. Chris and I have had many conversations on the phone and we have come up with plan "B". Chris explained that the H2 Kawasaki was never developed like it should have been. It had a very short production run and it was soon dropped in favour of more "environmentally friendly" four strokes like the mighty Z1. In fact, the drawings for the Z1 will have been on the table well before the H2 was launched. The Japanese knew that the writing was on the wall that would kill off the two stroke in the States. And lets face it, the States are where the sales are. So, like Chris told me, the H2 was never developed. in fact, although the "B" and "C" models look slightly different, the bike is fundamentally unchanged. In fact, the changes they made in the engine department were actually aimed at cutting emissions slightly over the original H2 and H2A models, and they lengthened the swing arm in an attempt to stop the bike from lifting it's front wheel so much. I am not convinced making an already flexy swingarm even longer would have helped with the handling but, who knows.
So anyway, plan "B". Chris told me that any porting on these motors just kills the power at the bottom end. Well, yes we know that you can't have it all. But possibly yes you can. Chris told me "Reed Valves" are the answer. He told me that if the H2 had been properly developed way back in the 70's Kawasaki would have probably fitted them as standard. By fitting Reed valves to this motor, you can have your cake and eat it. Chris convinced me that with reed valves, and fat "modern" expansion chambers I could have a "Torque Monster" as he described it. I could have a H2 that will put out approx 120 to 125 RWHP and be totally street-able and far nicer to ride than a standard one. He told me that with reed valves it will ride like a four stoke but put out the standard H2's max power at only 4000 rpm and climb with a linear power curve all the way up to about 9500 rpm. Sounds fantastic! And, to top it all, Chris told me, that he will do all the work, fit it with 34mm round slides and "UFO's. Then fit the whole top end to one of his engines. When it's ready he wants me to go down to the dyno with him and he will set up the carbs and everything, and when it's all perfect and I can see for myself the RWHP figures. He will remove the whole top end from his engine and I can take it home and just bolt it on to my bike. What a guy!
Chris will also be carrying out other work for me. Like modifying the clutch to take the 15 plate clutch conversion to stop it slipping with the extra horses. I am also having an extra bearing fitted to the timing cover to help to support the very heavy mag and ignition rotor, apparently at high revs it can be a weak area. I don't intend revving my engine up to 9500 rpm all the time, but it's a bit of extra insurance.
Chris's Drag Racing H2 with Reed Valves. 138.17 RWHP in the photograph, but eventually ended up with around 180 RWHP JEEZ!
Latest update: All the bodywork from my bike went to a friend of mine to be re-spayed. The colour of my bike was wrong, It was not a proper "Candy" Purple, just a metallic. Also, as soon as my friend saw it he told me the graphics where wrong. The "KAWASAKI" has too much white border. Do you know, I hadn't even noticed that. The previous re-spray was very good but there was some "bubbling" on the tailpiece. If the tailpiece had been ok I wouldn't have bothered re-painting it. My painter friend Stu, told me to go get the tailpiece and side panels blasted back down to bare metal so he could see what he was working with. He said he would strip the tank himself as getting a tank grit-blasted can be a nightmare later when you have to get rid of all the grit from inside the tank. I was amazed when I collected the tailpiece from the company who blasted it for me, it was a "right mess" it must have been covered with tons of filler as it was all dented and out of shape. The side panels were good apart from a small split on the right hand side one. Stewart told me they are all like that for some reason. He told me not to worry he has repaired and re-sprayed many Kawasaki triples and they all look really good when he has finished. He told me not to worry about the tailpiece, it was bad but not the worst that he has done. At this point I was not sharing his confidence and I was beginning to wonder what condition the fuel tank was really in underneath the paintwork. And what life my H2 had really had, I was beginning to doubt the mileage of 7500 miles. I left the parts with Stewart and went home feeling a little depressed.
The good news came a couple of days later. Stewart phoned me to say he had stripped the fuel tank and it was in excellent condition underneath the paint. We then decided that the tailpiece on my bike was not the original one as the rest of the bike was just in too good a condition to have a tailpiece that looked like it had been kicked around a garage floor for 20 years. This could also be the reason that only the paint on the tailpiece had bubbled. Stewart also told me that he had sorted out the tailpiece by opening up the welds and panel beating it back into shape then re-welding it. He just makes it all sound so easy ha ha. I know that Stewart won't use filler, other than the spray on kind, so it will be straight to within 3mm. that's seriously tight tolerances. I can't wait to see it when it's all painted.
The good news is it's all coming together. A couple of months ago I sent all the chrome parts apart from the exhaust pipes away to be re-chromed. All the chrome was actually very good, but not "perfect". I didn't bother to send the pipes as I will not be using them anyway and as you can see in the picture they are very very good. All the chrome looks like it was re-plated when the bike was restored about 17 years ago. I will just spray the pipes with WD40 wrap them up and store them. This bike sure is going to shine, I sent a lot of parts that are not chrome plated as standard, but will be on my bike.
I also collected my stainless steel parts that I had made by my "stainless man" this weekend. Loads of nice shinny parts to look at. I have had cylinder head nuts, engine mounting bolts, wheel spacers, wheel spindles etc etc made. here are a few.
These are a sample of what he made for me, yes he doubles up on some things so I can sell what I don't need to re-coupe some of the cost.
Powder coated hub, new chrome rim, stainless spokes and a chrome plated rear sprocket
Latest Update: Well I collected my re-sprayed parts from Stewart yesterday. What a lovely job he has done on them! The tail section looks like new. Halfway through the spray job Stewart asked me to call over to see if I liked the colour. Apparently the paint comes in a bottle of red and a bottle of blue and you have to mix them to arrive at the shade you want. Stewart had saved a small piece of the original paint that he found under the last re-spray that had been done about 17 years ago. Both Stewart and myself agreed that we would both like it better if it was on the dark side. Stewart pointed out that with a "Candy" finish, what you see in the dark is not what you see in the nice sunshine. He told me that if you make it look right in dim light it would look pink in the sun. I DID NOT want to ride a pink bike! I told him it was not going to be a "concourse" show bike so it didn't matter if it was "correct" or not. Plus from what I understand quality control at Kawasaki back in the days of the "H2" was not brilliant, and colours varied enormously. Anyway, I love the colour it's turned out, deep rich purple that looks good in the sun too.
Latest Update!:- I just managed to grab these pictures of the paintwork in the sunshine!
Well, it's been a while since I have added anything to this web site. All I can say is progress has been slowed down by the fact that Chris, the guy doing my reed valve conversion had an accident and has injured his arm. So all engine work has been put on hold.
I had been told that the Yamaha FZR400 alloy swing arm fits straight into my frame and with a couple of shock absorber mounts welded on, makes for a good swing arm conversion. I purchased one for next to nothing off ebay. Sure enough it fits straight in, however its not all plane sailing. The rear brake mechanism fouls the swing arm, so it's not a straight forward job. I shelved the idea, deciding to stick with the standard swing arm. After all, I have already had a stainless steel shaft and spacer made, plus had all the chain pulls chromed. So I am fitting new phosphor bronze and stainless bushings and going with the standard one. I also thought the FZR swing arm looked too big and wide for my standard size rear wheel.
I am hoping my front brake upgrade will go a little more to plan. I think with the extra horses I could do with some better brakes. I spoke to Chris about it and will be making me some mounts like he has on his bike so that I can use Suzuki 600 Bandit brake callipers. Chris also has a spare brake disc so I can have a twin disc set up. Change of plan once again. Having spoke to Chris again, we have decided to stick to a single disc set-up. The reason? well Chris tells me that he can lock the front wheel with the single disc set-up that he has, so any more braking power would be a waste of time if the tire is just too narrow to cope with it. I mean, you can not stop any quicker if you can lock the wheel, it's just dangerous!
I WAS having a something like this.
Yet another set back, Having purchased a really nice second hand brake calliper off ebay like the one above. I offered it up the bike, no way was there enough room on the spoke side. Chris hadn't realised I was running spoked wheels and not alloys like his bike. The calliper is just way too deep at the spoke side. I had to move to plan B. Apparently you can fit Kawasaki EX brake callipers, and it's quite an easy and effective conversion. I managed to purchase a couple on ebay. Although not in as good a condition as the bandit calliper, they are not too bad at all. I have stripped them down to be powder coated. As I bought two callipers I will be going to a twin disc set up again. I managed to buy a second brake disc from a guy on the Kawasaki Triples forum. I am taking both of the disc's to have the centres powder coated. The finished set up should look like this.
Well it's back to the engine again now. Things are beginning to move again. I have just received my modified clutch set-up from Chris. Basically it's a 15 plate clutch conversion, with a race clutch parts from Redline Motorsport in USA.
It seems to be quite a simple conversion, but apparently it works very very well on H2's. I am told that a H2 with a standard motor that's running spot on can slip the clutch. So, it would seem obvious that my reed valved beasty would run into some clutch problems. Although it all looks and fits very simple, it is clear to see that a lot of time and thought has gone into it. Obviously most of the guys that were and still are drag racing these old bikes had to come up with some solution to the problem of getting the clutch to be able to transmit huge amounts of BHP. The clutch on a Kawasaki H2 is actually a very small clutch unit when compared to the Suzuki GT750 from the same period. The basic answer is to add more plates, but that comes with it's own set of problems. How do you make room? Well, by removing some alloy from the centre hub, and using the thinner steel plates from the Kawasaki 500 triple it is possible to squeeze in some extra plates, more plates equals more surface area. This on it's own works fine apart from the problem of clutch drag, you could perhaps live with clutch drag on a drag racer, but on a road bike it could be a real pain. imagine trying to ride in heavy traffic with a dragging clutch. This is where Redline Motorsports in the USA came to my rescue. Larry and his team at Redline overcame the problem of the dragging clutch with a set of special springs and spacers. It must have taken a lot of development time to come up with their solution, however, it worked as their H2 drag bike ran down to a 8.39 second quarter mile with this set-up before they had any problems with clutch slip.
If you buy the complete kit and plates from Redline, it will all fit straight in, however if you just add an extra H2 Fibre clutch plate like I did. You will have to remove some material from the end of the tangs. You will find that one of your standard fibre plates is slightly smaller than all the rest, this plate sits directly under the steel ring that surrounds the clutch, it's smaller so that the tangs don't catch on the steel ring. When fitting the 15 plate conversion obviously all the plates will be in a slightly different position than they are in the standard set-up. With the 15 plate clutch you will have two fibre plates sitting under the steel ring, hence the need to remove some material so the two plates don't catch on the steel ring and prevent the clutch from working properly. All I did was hold my small plate and a normal plate together and held the tang onto my belt sander until I made a copy of the smaller plate, easy job and only took about 10 minutes to do.
Next came my bearing clutch release for good measure, Chris made me mine, however Redline do sell these too.
So, all in all it looks like the way to go with the clutch modifications. A good strong clutch and I don't need arms like Arnold Schwarzenegger to use it.
I have just received my incredibly expensive Wiseco pistons. I need to send them to Chris for him to machine some holes in the rear skirt for the reed valves to work properly. My Wife looked at me in disbelief when I told her I now had to have holes drilled in them LOL.
This "work in progress" is taking far too long. However I can see light at the end of the tunnel. I have my bike back on it's wheels now. It certainly looks good. Yesterday the sun was shinning and as the bike is now on it's wheels I thought it may be a good idea to wheel it out of the garage to take some photographs. The headlight was hanging out as I stripped and rewired all the switchgear last week. I thought, just put the headlight back in, fit the tank and side panels and take some pictures in the sun. Mmmmm! didn't quite go as planned. When I looked at the headlight I then noticed the wiring running from the clocks into the rear of the headlight was also perished. The outer sleeve was rock solid and cracked just like the switchgear wiring had been. So I ended up totally rewiring the clocks. By this time I had lost the sun, so no outside photographs Ha Ha. I did manage to take a few while the bike sat in the garage though.
Close up of the rebuilt front wheel
Rebuilt rear wheel with new rim, stainless spokes re-chromed adjusters, stainless wheel spindle and castle nut, and a chrome plated sprocket.
Re-chromed brake lever and adjusters. I also had the torque arm and brake rod chromed. Stainless wheel spindle and spacer.
Here are the latest pics of my Reed Valve Conversion.
Well, the sun was shining again today so I got the bike out of the garage to take a few pictures.
I must say I love the paintwork.
I have just taken delivery of a Sy-Tech clutch release, I purchased it through Rick Brett. If this release works half as good as it looks and feels it will be fantastic.It's a real quality item. From what I understand, the standard one fitted to my H2A is a bit of a weak link in the clutch system. The standard one runs in nylon mmmm I am pretty sure that if you had a set of heavy duty clutch springs fitted to your clutch like a lot of guys fit, you could easily strip the nylon threads. Like I said, I have the 15 plate clutch conversion fitted with Redline Racing clutch springs, so mine is not heavy anyway, but I am sure it will be very easy and smooth with this Sy-Tech fitted.
Well after much much thought I have eventually found someone who could make the expansion the chambers that I wanti to fit to my bike. They should match the porting quite well and I think they will look great. They come as a set of cones and I will have to weld them up myself. I wanted a set that actually looked "in keeping" with the bike and look a bit more like standard exhausts than the modern chambers with silencers attached. Getting three big chambers to fit the bike could be an issue though lol.
A giant step forward today!!!! I met up with Chris at North Weald to pick up my engine parts. They look fantastic! It was also good to meet the guy who had made the cones for my expansion chambers and brought them over from Holland so I could take delivery of them at the North Weald strip.
Three gorgeous barrels with new liners and reed valve blocks attached.
You can clearly see the modified piston.
And my 34mm round slide Mikuni's. Chris has modified them to take the oil feed directly into the side of the carburettor body. They are also fitted with lighter springs and I have the cable choke kits too, so that I can connect them up to my standard choke lever.
I found I had a minor setback with the oiling system. The new set-up required me to run a four outlet oil pump. I thought these were used on a number of Kawasaki triples, However it seems they were only ever used on the H2 "B" and "C" models. This unfortunately makes them quite rare. Luckily I managed to obtain about 95% of one through RB's Kawasaki triples forum. I used a few bits from my "A" model three outlet pump and Chris again came to the rescue with one part that I needed to put together the pump. I needed to make up my own oil lines because I couldn't get hold of the one that splits into three and runs into the crankcases, and the three that run to the carb bodies on the B/C models weren't long enough to reach my 34mm carbs. I made up my own in clear plastic tube. I quite like the idea that I will easily be able to SEE that oil is going to where it's needed.
New oil lines.
I am not using this generator cover, it's there just to protect the ignition etc during the build.
I did a little work on the bike today. I got all the oil lines connected up and connected all the cables. Today was the first time that I was able to actually feel the clutch action. It is fantastic! I would recommend the Sy-Tech clutch realease to anyone. It feels much lighter than the standard H2 clutch, and I have a beefed up clutch fitted to my bike. Very impressed!
I was in the garage today doing a bit to the bike, when I couldn't help but notice a lot of debris on the swingarm. It had me a little puzzled as I always cover the bike when I am not doing anything with it. I lifted the seat to re-connect the wiring from the engine to the ignition etc, when I noticed even more of this debris that looked a bit like biscuit (that's cookie if you are reading this over in USA) crumbs. It took me a while to work out what it was. It's the seat crumbling from within. Although the seat looks virtually in mint condition, It has problems within. It has been professionally recovered at some point in it's life, and the seat pan looks perfect. However, it looks like the foam inside is crumbling away. While I have been leaning on the bike while fitting the reeds, carbs etc I have obviously been been pressing down onto the seat. The foam is just too old I guess, it's turned brown and is crumbling every time I lean over the seat. the debris is bits of the foam falling down through the holes in the seat base. It looks like I need to take the seat to a professional for some remedial work. I figure that if it's falling apart just by leaning on it, I wouldn't last too long with me sitting on it.
Rick Brett comes to the rescue! Just as I was wondering where to take my seat for repair, Rick advertised on the forum that he had some pattern seat foams for sale. My problems solved! I quickly purchased one, and I must say they are a perfect fit. Well done Rick.
Well its been a while now since I updated this section. Things have moved forward over the last few weeks mainly due to me having a bit more cash to spend on her. Its a costly business building these old bikes, and this damned recession doesnt help.
Well, I tried to put my seat back together using the new seat foam and the old but perfect seat cover that I had removed. Mmmm no way was that going to happen. The problem was that the new seat foam was thicker than the old worn out foam that I had removed. The seat on the H2 has a stainless steel trim that runs down each side of the seat. This trim is bolted to the seat with some very small nuts and bolts. These bolts go through the seat cover. I found it virtually impossible to pull the seat cover tight enough over the new thicker foam to get the holes in the seat cover back into position. My wife and I fought with it for about an hour, using her hair drier to heat up the vinyl seat cover to make it soft and stretchy. Eventually I pulled it so hard I tore the cover. Bugger! I then got onto the phone the very next day to order a new one from Z Power. This time I took it to a seat builder, no way was I going down that road again LOL.
I ordered a pair of Hagon rear shocks, and I had them made especially for my weight (Excessive). This custom build service only cost an extra #10 and I considered it well worth it. Whats more, I received them the very next day. Thats some service!
I also ordered three sponge type air filters, I knew I needed this type of filter as I now have very limited space behind the carbs. These also arrived the next day. Great service again!
I figured I needed to order a drive chain and fit it before I took the bike to my friends at PHW Fabrications to have the expansion chambers welded together and fitted to the bike. The chain had to be on so that they could build my pipes and know that there was enough chain clearance. I did make the mistake of phoning my supplier and asking for the best D.I.D. chain they had in the size that I wanted. The mistake I made was NOT asking the price. Jeez! When it arrived and I looked at the invoice it was a whopping #108 plus VAT TRADE PRICE. When I had recovered I set about fitting all the above goodies. First the shocks, then the filters. I then took the chain out of the box and worried a bit about the size. Yes, I knew it was about 5 links too long. Not a problem as I have a chain breaker, I was more concerned about its physical size. These old bikes never had X ring chains in their day, and were not designed with them in mind. It was the gap between the engine sprocket and the clutch release mechanism that I was worried about. I offered the chain up to the bike, it was close, very close but it just missed the end of the Sytech clutch release. Now if my memory serves me well, the standard clutch release is a little larger so it could well have hit it if I had been running the standard set up.
At this point I though mmmm I will get out my camera and take a few pictures of her for the web site. All the bodywork I keep in my office, so I thought mmmm I will pop the bodywork on for the pictures. It was at this point that I realised that the tank would no longer fit on the bike. I had spent ages fitting the throttle and choke cables for the smoothest possible run, only to find that all the cables have to run inside the frame tubes and not outside as I had run them or the tank wont sit back on the frame Jeez! Back to the drawing board.
No, the Rev counter cable isnt staying in that position. Just to stop it dragging on the floor while I wheeled it out of the garage.
You can see from these pictures why the sponge air filters were needed. Just after these pictures were taken I loaded into my van and took it down to PHW Fabrications to have the expansion chambers fitted. The chambers came as a set of rolled cones so I needed someone who knew how to weld them and actually make them fit the bike. Obviously the main stand will have to go, and I am having a new side stand fabricated to mount further forward in the standard exhaust mount that you can see clearly the next to last this picture. Plenty of space is required underneath to get those fat chambers under the bike.
Forward a few weeks! I went down to London in the van to collect my H2 today. PHW Fabrications had done a lovely job of the pipes. I also asked them if they could fabricate an alloy chain guard for me. I wanted a nice shiny one but the standard one that I had was not good enough to send to the chrome platers, so I figured if they could make me one from alloy, I could polish it up to look like chrome. What a great job they made of it. Virtually a exact repro in alloy. Just need to get my buffing wheel on it now.
It looks like there is no ground clearance with those big pipes, but actually they are not too bad. PHW have managed to tuck them well underneath.
When I got the bike back home I took off all the choke and throttle cables. I did mention that having spent ages fitting them for the smoothest run, I then found that the tank wouldnt sit properly. I needed to take them off anyway as I had ordered a set of UFOS from America. If you have not heard about them, UFO stands for Ultimate Flow Optimiser. Basically an aerodynamic piece that fits into the bottom of the carb slide on round slide Mikuni carbs. Gas flowing the carb if you like. I have heard good reports on these, and they really do work. Giving better throttle response and a broader power band. Simple enough to fit, although they do take a little time. More information on the UFO can be found here. http://www.thunderproducts.com/
The UFO fitted
Once again I spent ages re-routing the choke and throttle cables. I seem to have found an even better route for them as now I can use lighter springs in the carbs. I actually ordered lighter springs but I found they couldnt pull the throttle fully closed, so I had fitted the standard springs. With this new routing the light springs work fine, making the throttle much lighter.
Well, I took my expansion chambers to be chrome plated about three weeks ago. I received a call to say they were ready to collect yesterday. Lovely job! I couldnt wait to get them fitted. I got two on and rushed in to get my camera.
Well things have moved on a little since the above picture.
I fitted my new alloy chaingard that PHW fabrication had made for me; its a very very close copy of the original. I wheeled the bike out onto the driveway and leaned the bike onto its sidestand only to find that I carried on leaning. I had asked PHW to make a mount so that I could bolt it to the original exhaust mounting hole. They had told me that although they had done what I had asked, they were not happy with the strength of the exhaust mount that I had bolted my sidestand to. They told me it could work but they really needed to strengthen the mount up, but didnt want to weld my powder coated frame without my permission as it would spoil all the powder coating. It had worked a couple of times, but this time it just bent the mounting as you can see in the above picture. After sitting looking at it with a cup of coffee for a while, I believe I have come up with another solution that wont require any welding. I have a guy on with it at the moment, what this space!
I had decided to use the standard fuel tap as I really want the reserve, most replacement taps dont seem to have this. I drilled into the side of my centre carb to fit a vacuum take off for the fuel tap. The inlet pipes on the 34mm carbs are a different diameter to the pipes on the tap so I searched the internet to find some little adaptors to join the pipes together.
After I had fitted the fuel pipes I decided to see if it would actually start. The moment of truth! I poured a little fuel into the tank and turned the tap to prime. I was happy that none of the fuel pipes were leaking. I removed a spark plug and asked my wife to look for a spark when I kicked it over. Yes! A nice big spark, so I refitted the plug and kicked it over. On the third kick there were signs of life, on the sixth kick it was running! WOW! It was so nice to hear it run after all this work. I held the oil pump fully on with my hand and watched the oil get drawn into the engine, everything was going to plan! It is loud, and has a very staccato crackle to the exhaust sound, no doubt due to the quite flat exhaust port ceiling. There is no doubt it sounds like a racer!
This picture with the young girl holding her ears is just PRICELESS!!
Well, its been quite a while since I have added anything to this page, so here goes!
When the bike was completed it had one or two teething problems which were to be expected. Nothing too drastic though.
I had a bit of a problem with one of the head gaskets leaking; it was blowing into one of the stud holes in the barrel. This caused it to squirt a very fine jet of oil from the head bolt washer. The oil appeared to be bubbling from the head, I thought I had a cracked head and started trying to locate a second hand head. I took a while for me to actually work out what was happening. I torqued done the heads a little more and the problem was solved.
The next issue involved the new oil system. I noticed that instead of having nice clean red engine oil in the oil pipes, the oil was turning black in the pipes. One or more of the one way check valves that are integral to the banjo bolts must have given up the ghost. This allowed crankcase pressure to actually blow the oil back up the pipes into the pump and out into the lines that lead to the carbs. This basically meant there was no oil feed to the crank, and gunge was heading to my carbs.
What I did was drill out the valves so that the banjo bolts were just that, simple banjo bolts. I located three separate check valves from the internet and fitted them into the lines. These are definite one way valves so nothing would be blowing back.
The new check valves
As a temporary measure, to make sure all this part of the oil system is functioning properly. I have refitted my three outlet oil pump and run three separate lines to the crankcase inlets. This of course means there is no oil being fed to the barrels & pistons. So, for the time being I am putting 32/1 premix into the fuel tank.
The pump has been wired on at just over the tick over setting.
After a few trials with the premix/oil pump set up I decided to once again refit the 4 outlet pump and feed oil to the carbs and do away with the premix. But after spending a couple of hour messing about with oil lines and T junctions etc. etc., I thought there are just too many junctions in these oil lines and I have once again returned to the premix/oil pump system. I like it because it looks much better without oil pipes all over the place, plus, keep it simple is my motto. Its not really an inconvenience for me to use premix because I dont use the bike for touring. I simply mix up a couple of gallons of fuel in my garage and this will last until I return home. I say fuel, as I actually run the bike on unleaded with an octane booster plus 32/1 premix with Motul 710. The oil tank is full of Motul 710 as well, with the oil pump fixed at just over tick over setting.
I didnt like the look of those large check valves that you can see in the photo above, so I made up yet another version of my oil lines. I managed to track down some small plastic check valves from the USA, and these look much nicer.
My latest version of banjos with check valves.
The oil system works, and works well. I have removed the left hand cylinder barrel many times and there are no marks or scuffing on the piston or cylinder bore, so I am happy with it as it is. Yes, you may ask, why does he keep removing the left hand cylinder barrel. Well I dont know if you have noticed but the oil line banjo for the left cylinder now sits under the reed valve housing. So close in fact, that I had to remove some metal from the top of the bolt. So, changing the oil lines is quite a major ordeal. Glad it seems to be sorted out now, and I dont have to take it off again.
As you can see, its a tight fit.
Since I posted this article of the internet I have read quite a few comments regarding my Kawasaki H2. One in particular commented on the fact that I should have put as much time, money and effort into the frame/handling as I have with the engine.
Quite a fair comment, however the most important thing for me was to keep it looking like a 1973 Kawasaki 750 H2. The H2 was a bike I have wanted to own all my life. Back in my youth I resisted the temptation based on the fact that they had an evil reputation for both handling and fuel consumption, I figured that the way I rode my tuned Yamaha RD250 after passing my test, If I had bought a H2 I would probably not be here now. Plus, with MPG figures of 18 and less, if I hadnt killed myself I would have been broke all the time. Hence the reason I opted for a Honda CB750 (big mistake LOL)
I loved the look of the Kawasaki 750 H2 back in the early 70s and I love it now, Yes I could probably make it handle far better by fitting upside down front forks and monoshock rear end, or would I? I am not totally convinced that adding modern suspension to a 70s frame would make it 100% better. It would however for me, totally spoil the looks of this classic 70s icon.
Which brings me to my point about the H2, When I got mine and rode it I wasnt spit off into the nearest ditch, I wasnt thrown off the back due to the mind blowing acceleration, I wasnt thrown off when it went into a violent lock to lock tank slapper. I can actually remember thinking what was all the fuss about It rode and handled about the same as any other bike from the 70s. I believe all the comments about evil handling, a frame with a hinge in the middle etc. etc. were made by people who have never actually rode one. The main problem with Jap bikes back in the 70s were tires and shocks. Hence the reason everybody fitted TT100s or Avon Roadrunners or something similar. Rear shocks were also a bit suspect, but again most of us fitted Girling or Koni shocks or something else, we often put a couple of spacers on top of the front fork springs to stiffen up the front forks. Mine is fitted with Hagon rear shocks especially made for my weight, it is fitted with phosphor bronze swing arm bearings and it handles fine for an early 70s bike. Remember this year is the Kawasaki H2s 40th anniversary, yes its 40 years old. It will never handle like a modern bike; take it for what it is. A piece of history that will never be replaced, its noisy, smelly, and wild and I love it.
Well, like it says at the beginning of this page, completed, well nearly are these projects ever finished? As time moves on I think what else could I do to improve it? Well, there are a few things that I have planned for the bike before its 40th birthday (mine is a 1973 model). Firstly, the front forks. The front forks need something doing to them. The low speed damping is rubbish. I know that nearly all Japanese bikes of this age were fitted with poor suspension. Generally they were over-sprung and under-damped. My Kawasaki is no exception. The Hagon rear shock absorbers that I had made to my weight requirements work perfectly, however whether its due to the fact that the rear end is much firmer, or the fact that my main bike is a BMW with the telelever front end that doesnt dive under braking, and I am used to that. But the front forks dive way too much for my liking under braking. When I give it a hand full of front brake it feels like the front wheel is going under the engine. The solution is the PD fork valves that I will very shortly be fitting. I have ridden a GT750 that was fitted with these forks valves and I must say they really do work. You can find out more about these PD fork valves on this website. I now sell them, as I believe all classic motorbikes from this period would benefit from them. They are very reasonably priced and they retain the looks of your classic, while improving the handling no end. While still working in the front fork area, I am considering fitting a fork brace to keep them both working together, and I may fit the bike with a braced swing-arm. Years ago I used to have a Suzuki GT750 that I fitted with a Dresda box section swing-arm and the results were very good, it definitely made a difference. Can anyone out there help me with that? Email me please!