1988 Kawasaki KMX 200 - A2 - rebuild/restoration

[dangerousdave]

While waiting for my top-end to come back from the tuners, I had a go at the KIPS valves. When I pulled these out of the cylinder they were in a sorry state, completely covered with carbon. This carbon causes the valves to stick and can obstruct the air flow.

These valves are pretty rare now, and no longer available from Kawasaki. I didn't want to damage the faces by scraping the carbon off with a screwdriver.

After a couple of 24 hour soaks in Caustic Soda, and a lot of scrubbing with Brillo pads, I managed to get them looking half decent.

...now, if only i could remember which is the left hand valve .... !
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

So, now the barrel and piston have now come back from the BDK Race Engineering I'm getting ready to refit the top-end.

I haven't seen the work on the barrel & piston yet as it's been delivered to the workshop, where the bike is stored. However, what has been done is the following ....

1) Modify the piston skirt to clear the crankshaft (removal of 3mm off the skirt)
2) Match the iron liner to the cylinder barrel (previously a real mess)
3) Port & Polish

They called me and told me that the angle of the boost port was completely wrong on my bike. This is where the cylinder had been sleaved and the rebored - so the port was pointing straight out of the exhaust ! This has now been corrected.

There are a couple of other jobs which need to be done:

1) Flush through the radiator to make sure it is working at its optimum.
2) Rejet the carb - larger main jet to keep the engine cool at WFO
3) Respray the cylinder with hi-temp paint
4) Re-cut the V-Force reed-valve for smoother air-flow
5) Repack the silencer

I have new seals for the KIPS valve, to eliminate the annoying oil leak, and the valves themselves have cleaned up well so they should now work nice & smoothly.

Its been out of action for a few months now, so looking forward to it coming back together.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

So, got the top-end back from BDK racing, they'd done a good job of reducing the piston skirt and matching the liner to the cylinder.

I got started with the top-end assembly.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Beamexican]

Looking good mate, been watching this with interest as i've just rebuilt a kmx125 i bought in boxes.

Like to buy a 200 eventually to go with it when i've got this one finished.

Saw this on ebay thought you might be interested, not sure if/ how well it would work and £25 seems a bit steep but i reckon something crude could be knocked up at home to test the idea, might try it on my 125.

https://www.ebay.co.uk/itm/KAWASAKI-KMX200-KIPS-BOTTLE-ADAPTER-PLATE-SCREWS-IMPROVED-LOW-DOWN-PERFORMANCE-/380409900402?pt=UK_Motorcycle_Parts&hash=item5892326d72#ht_851wt_932

[dangerousdave]

Hi mate - well done on the KMX125 rebuild. Be good to see some pics etc.

I ordered one of those KIPS bottle adapter plates on Tuesday. Its a mod i heard about a while ago & as it is supposed to boost the low-end without changing the top-end, thought its worth a go. I ordered up a Twin-air filter also, to do the best job of protecting the new top-end from any muck getting in it.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Beamexican]

Yeah, will try and get some pics up soon, where did you get the twin air filter if you don't mind my asking as i had to buy a genuine kawasaki one and they seem hard to find, is the kmx200 one a tall cone shape?.

[dangerousdave]

Got the Twin Air filter from Motocross world.

https://www.motocrossworld.com/site/scripts/products.php?category_id=3831

The illustration picture there is wrong (at least i hope so!!) as it is actually a long thin thing - like the standard filter.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Beamexican]

Cheers might buy a spare anyway, not sure if the 200 bottom end is the same as the 125 but if you come unstuck needing any parts give me a shout as i've got a near complete stripped engine

[dangerousdave]

Just a couple of updates.

1. KIPS bottle spacer.

This is a mod i'd heard about a few times. It increases the volume of the KIPS resonator chamber, altering the tuned length of the exhaust. Theoretically this gives more low-midrange power. Top-end power is not affected, as the resonator chamber is shut by the KIPS valves by 7k. If anybody is interested I'll test the bike with and without this mod fitted and see what the difference is.

They are also available for the KMX125.

2. Back wheel

Managed to track down a half-decent back wheel to replace the badly corroded one on the bike at the moment. I've kept with the 125 back wheel, as it is an 18" rim instead of the 200's 17". The 18" rim gives much more choice of tyres for off-roading, as it is the common size for enduro bikes. the 200's 17" wheel has a very limited selection of off-road tyres.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[Arctine]

Hi, very good thread.

I have myself just picked up a 1988 kmx 200 for £400 from my brother that I'm restoring.

It's been sat for a while so the big end bearing is making a knocking sound due to it drying out and I'm hoping this will disappear once it's been ridden for a week or so. If not then I've got a con rod kit to replace it. Other than that, the piston and barrel etc are almost new as my brother spent £600 on new ones. It runs quite well other than the knocking, obviously.

A few questions if you don't mind. My clutch is very short and stiff. I'm not sure but I'm guessing my brother may have rebuilt it with the heavy duty springs you mentioned earlier. This is all well and good but is there any way to soften the clutch?

For some reason the tachometer, even when connected, does not work. The speedometer does thankfully. Can you help me troubleshoot why it may not work?

When revving the bike, it will start making a funny noise at higher revs, almost as if something is rattling very quickly. I've got a feeling that this might be because the exhaust is rubbish. I've ordered a new big one exhaust with a chrome plated front pipe so I'm hope that will solve that problem.

When riding the bike, as soon as the revs get to a certain point, and it's hard to tell what rpm without the tachometer, the engine will distort and give up accelerating. Any thoughts?

Finally, when revving the bike, it takes a little while to go back to tick over. I've matched the etchings on the oil regulator to get the mixture correct. What other things could I check to get it better?

Thanks for any help!

[dangerousdave]

Finished off rebuilding the top-end this weekend. Mostly the time was spent cleaning up bits and checking stuff over.

After the barrel was finally back on and bolted down I had a look over the exhaust. The bike came fitted with a KX silencer which was a bit worse for wear. I had this apart to for a good clean up and repack. It is about half the weight of the standard silencer. I was using the standard Kwack silencer for a while before but it was running so hot it was melting the side panel !

I decided to stick with the original expansion chamber for the time being, as it gives a good spread of power. The other chambers use a shorter tuned length to raise top end power at the expense of power everywhere else.

The exhaust got its regular scrub up with a wire brush and some high-temperature paint. If anybody knows of any method of painting these up so they don't rust after a couple of months I'm all ears !

The radiator got flushed out with Holts Speedflush. This stuff seems to shift a fair bit of build up out of the system. For some reason the 200's have a reputation for boiling over, although I've never had this myself, even on the longest days greenlaning.

As the engine has been apart for a while, the oil-pump was checked for output, which on the 200 should be within 2.8 - 3.4 cc over 3 minuites. This bike was pumping out fractionally more but considered this healthy.

The bike fired up easily. The rebuilt engine sounds good, very quiet.
I did a short ride on half-throttle to begin running the engine in.

There's still a lot to do with the bike. Once the engine is bedding in well there is the fine tuning of the carb, trimming back the V-force valve, fitting the KIPS bottle extender and then starting to look at the addition of a larger carb. I have a few suitable carbs, the Mikuni TM28 and TMX30 powerjet, which have been reported to work well on the KMX, along with some other carbs with which there is much more involved to fit.

Chassis wise, the suspension is going to need looking at as its lacking in damping, and has excessive sag. I have a spare rear shock (with the reservoir which the later models had). This will most likely be fitted to sort out the back end.

I'm hoping to have it in a robust state for doing a few trails in the summer, but still a way to go yet.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

Just a little update.

Now the engine is rebuilt, the "death rattle" has gone and the compression is healthy, I can move on to the next most "broken" part of the bike.

This is the rear shock. Although the chrome looks good it seems to be lacking in any sort of damping, and despite being on the highest pre-load setting, sags excessively. Any bumps turn it into a pogo stick and speeds above 50mph can have the bike bobbing about all over the place on the road.

I managed to track down a secondhand unit with the gas reservoir, which the later models had. I'm unsure of the advantage of this unit but its generally known for being a better shock, an upgrade on the unit I have. I've been advised that using an alternate reservoir transforms the bike, giving a much greater range of damping adjustment - as road and off-road riding need completely different settings. Bit of a faff having to re-gas the unit to swap the reservoir, but will be worth it.

I haven't fitted the KIPS spacer yet, been waiting until a few miles are under the wheels to change it over, so I can see how much effect it has.

The KX silencer I'm using is ok, but incredibly loud. I'm going to try an Arrow, and see how that goes. As far as the expansion chamber goes, although the original KMX200 pipe does work well on the bike, giving a good spread of power, I'm curious what more can be done. I've found a cheap dented secondhand exhaust which I'm going to cut open as there is apparently a "second wall" of honeycomb metal in there, which although keeps the bike quiet, does nothing for performance. Then it can be welded up again, and I'll test how the bike runs then.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

Tore the brakes down last weekend, replaced the rear seals and made the best of a corroded piston with some used wet-and-dry. This will need to be replaced soon but has gone back together for now, with braided lines fitted.

I was looking at getting the rear shock serviced - sent away for a refresh - unfortunately the workshop decided it was too far gone with some corroded chrome so its back in my hands now.

I've tracked down another shock - i might have a go at rebuilding it myself - bit cheaper than £140 odd quid lol

Managed to find somebody to machine me up a new steerer tube for the KX yokes to get the stronger front end fitted. The KMX forks are leaky and generally in a sad state so will transform the front end. I'll be sending the yokes off in the next few weeks.

Engine wise i've found a KDX200 FMF Gnarly pipe which others have successfully modified to fit the bike. I thought long and hard about attempting this but the lack of any alternative pipe made for the KMX 200 has made the decision a lot easier. The Big One is the only alternative pipe, but this is actually a 125cc pipe adapted to fit, so I never found this worked well at all. In comparison, the KDX 200 pipe is at least made for the correct engine size so I'm sure this will bring about a much better result than the Big One.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

Brake rebuild etc
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[effit]

Keep up the good work matey...

[dangerousdave]

In the post ready for test fitting & measuring up.

FMF pipe from a KDX 200.

Manifold is completely different - o-ring and spring instead of bolted, location of exhaust port is central instead of exiting left on the KMX so fair bit of work to fit.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

few new bits done over the weekend. doesn't feel like loads of progress, and nothing really finished, but getting there slowly.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[effit]

Keep up the good work bud!

What cleaning product did you use on the calipers?

[dangerousdave]

[effit]

[dangerousdave]

not bad for 10 mins work. caliper been sat in the shed for a year so pistons aren't moving too well so will have to have them out and cleaned up.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[dangerousdave]

Finally, got the KX yokes sent away to have the steerer tube modified to fit the KMX headrace bearings. Should be back in 2-3 weeks

This leaves the steering lock to sort out. Been advised that due to the shape of the KX bottom yoke this leaves a tiny turning circle.

Easiest thing to do would be to grind back steering stop on the frame but if i fit the standard forks back on at any point i'd be stuck with a excessive steering lock. Something to think about.

Anyways, front end is complete and ready to go in once the yokes come back. The KX brake caliper needs a rebuild, but the pads are good. I'm considering getting hold of a secondand KX master cylinder to match the KX caliper.

So with the higher front end, the back will need to be raised to suit to prevent it turning into a chopper. This seems relatively straightforward in comparison by fitting shorter links in the rear suspension.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[WJE]

Nice project.
Very interesting read

I too am restoring a kmx200 (my 3rd one).
The kmx200 has a lot of sentilmental value to me, as its the bike I learnt to ride on when I was 13 (now 25) and then it was stolen.
So, this is my 3rd. I was going to use it as it is, as I couldnt track down any parts. To most people, it would be clean enough, but I really dont like the frame being tatty (and had the tail cut off grrr)
It came with a terrible headlight, ive managed to locate all the correct stuff Brand new mudguards, brand new handguards etc etc.
Its not going to be completely original, as I am still going to use it.
Will have a Big One pipe, and it has Renthal Fat bars. Ive removed the enduro rear mudguard mounted tail light, and fitted an original uncut original light etc.

I notice you said the Big One pipe is usually a modified 125 exhaust, but they do also sell one for the 200 I had them on both my previous KMXs.

Very interested to see how the Powervalve spacer pans out. As I have been looking at them on BDK for some months now, and was hoping to see an independant review before I buy one. Although, they do seem to have done some previous work with KMX200s.

[dangerousdave]

welcome fella and good to see another kmx200 project coming on.

put a thread up and keep us updated with its progress

As for the KIPS spacer, wasn't a big difference when fitted to my bike, but supposed to give a couple of hp across the midrange.
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1988 Kawasaki KMX 200

Previous: Yamaha YZF1000, ZZR600, KMX200, DT50, KX80, CG125, PF50

[WJE]

Thanks, and will do I have a zx636r which I use alot, so this is always going to be on the back burner of that. The difference is, my 636 will be long gone before this ever will
Havent got any pics from when we got it (my Dad brought it, and it never turned a wheel for 18months lol), but when I collect more pieces I will I need the rear bit off the subframe before I strip it

Yeah, I did see it was supposed to give better bottom end to mid range, but always wanted to have an actual persons view