1986 KDX200 rebuild

I recently got my hands on a 1986 KDX200 (FREE!) that I'm going to fix up and sell to a friend for the price of parts. The bike is is surprisingly good condition for the price (again, FREE!), It needed the cylinder re plated (Currently at Millennium Technologies as I write this).

Here is the bike as it was when we got it:

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It also came with a spare front fender, gas tank, swingarm assembly, rear wheel assembly, some aftermarket silencer, and some tires. And a NIB Weisco piston (Off with Millennium, too).

Here's some close ups:

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Here's the KIPS before and after some TLC with degreaser and scotch brite:

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While we waited for the cylinder to come back I decided it would be wise to tear into the rear suspension and check/grease all the bearings. This was a good idea, one side on both the swingarm and linkage had the bearings rusted and siezed and all of the bearings were caked with hard grease and dirt. Not surprising...

The shock also needs some work. It feels like pulling chunky soup through it and I'm pretty sure it's about out of oil. I've never done a shock rebuild before. Looks like I'll need a rear shock seal kit

http://www.rockymountainatvmc.com/productDetail.do?navType=type&vehicleId=1340&navTitle=Suspension&webTypeId=129&webCatId=13&prodFamilyId=19111

How much oil will it take? Any recommendations on what kind? No fancy racing stuff needed. Will I need anything else?

Some of the shoulder bolts in the linkage assembly look like they've been replaced with standard bolts:banghead:... I haven't decided if I'll order new ones, or machine off the threads in the contact area and make a bushing... Either way, they aren't staying like that!

Here's a pic of the suspension components all cleaned up (missing some):

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I still need to polish up the linkage sleeve and fix some damage to the linkage itself.

Once the suspension is done I'll probably move onto fixing up the exhaust. I'll probably end up stripping ad re-painting the whole engine, apparently, the cylinder will be naked when it comes back from Millennium. It could use it anyway.

So far I'm in:

$190 for the cylinder.

$24 for a new front inner tube.

$50 ish for a manual and engine seal kit

$5 for some new grease zerks for the linkage assy.

And I'll be ordering

$40 ish for new bearings for the swingarm and linkage

$34 for the shock seal kit

$? for some new shock oil

$ 25 ish for new linkage bolts

For a total of around $370 so far. It will probably also need a new pair of grips and other stuff and we work into it more. I'm happy!

No one's interested? And I thought you guys loved green!:smirk:

I took apart the rear shock to make sure everything was good before I placed the order for the seal kit.

Here's the horrid black goo that came out of it:

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There wasn't that much in it either, looks like most of it leaked out of the main seal. The caps, ans clips were good and stuck in there. I got the one for the reservoir pushed in with just finger pressure and then removed the rusted clip, and popped the bladder assembly out with a little air pressure on the other side.

For the main cylinder though I had to make a tool out of tube so I could tap the seal assembly in with a hammer. I got the other rusted clip out but I had to use an adapter and hydraulic pump to get the piston/ seal head out of it. Again, it was pretty gummed up.

Here's it all disassembled:

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The good news is with a little cleaning it looks like everything is in pretty good order. I'll get the seal kit and bumper and it should be good to go! There was a little corrosion on the shaft, but after a little polishing on the lathe with some 600 grit sandpaper it looked pretty good. There was still some small pitting but hopefully it won't be too bad on the seal. It's about half way up so it probably won't be going through the seal too often anyway.

When I removed the nut for the piston, it pulled the top thread off the shaft. Are the nuts tack welded on or something? I thought it was pretty weird and it was a pain to get it cleaned up again!:smirk:

The bearings, seal kit, manual, and engine gasket kit are all in the mail. Hopefully stuff starts showing up soon so I can start assembling everything!

Well, it's all done! I ended up at about $735 total including fluids. Most of that came from when I cracked open the lower end to see metal shavings and a gear missing a tooth!:ride: I ended up replacing the crank bearings, oil seals, and swapped out transmission gears. I also could have saved some on shipping if I took everything apart and THEN ordered parts... The shift shaft also had a horrible bend in it (I was surprised it was still working!) that I fixed, and later found that that had put a dent in the case cover (about .035 gap!) when I went to put oil in it. I got that fixed, too.

In total I:

Put new bearings in the swingarm and fixed the bent chain guide bracket.

made a new bottom spacer for the chain guide. The old one was worn through to the bolts!

new bearings in the linkage.

fixed bend in linkage and off round bolt hole.

made a shoulder bolt for where the shock is mounted to the frame.

rebuilt rear shock

repainted all rear shock components.

had the cylinder replated, then painted.

decarbonized the exhaust, fixed some large dents, and repainted.

rebuilt lower end, including new crank bearings, gaskets, oil seals and gears.

made a magnetic engine drain plug out of a larger than stock bolt (PO had stripped the threads bare)

fixed bent case cover.

replaced rear wheel bearings.

fixed the rear brake.

cleaned and bled the front brake.

bought a speedometer for the front wheel. I don't have the computer for it, but it needs to be there as a spacer for the wheel.

I'm probably forgetting something... I took apart every assembly on that whole bike, cleaning and replacing parts where needed. Aside from the worn plastics and paint, it's practically a new bike!

Here are the final pictures after the first ride after break in:

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It felt real good to get it all put together and ride it after all that!

wow, I dunno how I missed this thread. Good work, the bike looks great!

wow, I dunno how I missed this thread. Good work, the bike looks great!

yea me too, and im on all the time.

great find, looks good for not putting much into it.

yea me too, and im on all the time.

great find, looks good for not putting much into it.

Me three! :lol: That is a clean looking '86 and I bet it is a helluva nice ride as well! :ride:

Thanks. I've got a lot more pictures, but looking back they're kind of boring. Mostly just before and after shots of the pieces. I'll see if I can find any interesting ones.

The bike runs well, and after I got the secret start handshake (Choke on, quarter throttle and a swift kick!) down it starts first kick! I may have the KIPS installed wrong, I'll have to check it out tomorrow. The manual was referring to marks that weren't there on the cylinder to get the valves aligned.

It drips a little fuel out of the bowl drain line. I think there may be some crud in the drain keeping it open, or maybe the float level is too high. The only reason I noticed it was because it was raining when I took it out for a test ride and saw the spots on the wet road.

Looks like this week is going to have some good weather (FINALLY!) so it should get broken in pretty soon!

I got the KIPS installed the right way and took it for another test ride. It runs a lot better now... Go figure!

The drops I was seeing on the ground the other day was actually mix leaking from the KIPS rod. The seals were completely shot so I replaced them and presto, no more leaks!

Awesome! Now get us some video of you ripping it! :lol::ride:

Cool rebuild! Congratulations on getting one up and going.

For future reference, the top of the shock rod is peened over and should be ground flat with a grinding wheel (or patience of Job and a flat file).

GREAT JOB ON THE KDX!  IM HAVEING THE SAME PROBLEM WITH THE EXAUST VALVES. THERE ARE NO GROOVE ON THE CYLINDER TO LINE UP WITH. I WAS WONDERING HOW DID YOU LINE THEM UP CORRECTLY? IN THE MANUAL IT LOOK'S LIKE THEY JUST GO IN WITH THE DOT FACEING STRAIGHT FORWARD. IS THAT THE CASE?  ANYONE ELSE HAD THE SAME PROBLEM? THANK'S!  GDHIC

Very nice!

762SPR, I HOPE YOU STILL CHECK IN ON THIS SITE. I AM HAVEING THE SAME PROBLEM WITH THE THE GROOVES THAT DO NOT EXIST ON THE CYLINDER TOP.  IF ANYONE ELSE KNOW'S HOW TO LINE UP THE EXAUST VALVES, KIPS ON A 1986 KDX 200, PLEASE CONTACT ME AT  GERALDDUNNREMO@AOL.COM  IM AT A STANDSTILL BECAUSE OF THESE STUPID VALVES. NEED TO LINE THEM UP.  LIKE HE SAID, THERE ARE NO GROOVES AS THE MANUAL SAY'S THERE IS!  ONOTHER WAY COULD BE IF ANYONE KNOWS IF THE VALVES ARE OPEN OR CLOSED WHEN MOTOR IS NOT RUNNING. THEY ARE VISIBLE FROM THE THE EXAUST PIPE HOLE.  THANK YOU!  JERRY  / GDUNNHIC

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