KDXRIDER.NET

Hello I got a new-to-me 1988 KDX 200 last week. I plan on tuning this into a trail beast. My girlfriends dad is a KTM guy and convinced me to try out dirt bikes. I come from the street bike world and have rebuilt 6 mid 80s Japanese street bikes and a couple of 90s bikes. This is my first dirt bike.

When I first got it the owner described an issue where it wouldn't idle and felt like it had no top 3nd power. They put a new top end in it, which I later confirmed, a brand new wiesco 66.0 piston in it.

I haven't ridden it yet, I got it to start, but it needed throttle to say running. Sounds like to me the idle circuit was either too lean or too rich, probably too lean. The carb that was on it was a Keihin PJ series, not the original carburetor, also there were massive gaps in the boots. I checked compression after it was slightly warmed up and its about 125 PSI. With good enough compression and spark, I'm pretty sure it just needs a properly jetted OEM carb.

I sold the PJ series, and now I have new carb setups for both the 1987 and 1988 model, a 35mm mikuni VM34 with appropriate jets and a 35mm Keihin PWK (non quad vent/airstriker) I plan on using the Keihin.

Right now I the bike is stripped down to motor and frame. I'm going to start building it as follows:

Rebuilt caliper, new brake line, Rebuilt MC, new rotor.

New steering, swingarm, linkage, and wheel bearings

Rebuild forks and rear shock with proper springs for my weight and riding style (.41kg/mm front, 5.4kg/mm rear)

New tires, mousse inserts and spoke covers

New chain, sprockets and chain guide block and rails

New controls, cables, handlebars, handguards and either number plate or light.

New coil, and stop switch

I'm not a fan of rattle can paint, or painting dirtbikes so it's going to be wrapped. The color scheme for this bike will be gray with white and red accents. I haven't decided on the wrap yet.

Other quality of life upgrades will include new pegs, shifter, gauge and gripper seat cover, but aren't necessary for me to ride.

Code name 'TRAILGHOST' for the color and application of the bike. Here are some pics:

Congratulations on the KDX.

Good luck with the project. Take your time.

One note, the front brake hose needs to go inside the fork leg, not out. It can get caught on roots, limbs, rocks, etc.

KDXGarage wrote: ↑01:25 pm Jun 04 2022 Congratulations on the KDX.

Good luck with the project. Take your time.

One note, the front brake hose needs to go inside the fork leg, not out. It can get caught on roots, limbs, rocks, etc.

Thanks for the tip! I got a new braided hose and I'll route it properly.

Updates: New steering bearings, swingarm bearings, wheel bearings, and linkage bearings. Cleaned up clutch cover and triple tree. Waiting on fork and shock springs

HEY! Looking good there.

Where did you buy new linkage bearings for the dog bone? Did All Balls have them? I seem to remember they might have had a kit at some point.

If the rubber chain guide blocks are dried out, a guy on eBay (or two) make homemade replacements (and carb and airbox boots). Hotfootmoto and another seller.

KDXGarage wrote: ↑01:55 pm Jun 05 2022 HEY! Looking good there.

Where did you buy new linkage bearings for the dog bone? Did All Balls have them? I seem to remember they might have had a kit at some point.

If the rubber chain guide blocks are dried out, a guy on eBay (or two) make homemade replacements (and carb and airbox boots). Hotfootmoto and another seller.

The kit #27-1106 from all balls for select kx250 and kx500 has the linkage arm bearings and dogbone bearings. Also the linkage arm bearings are the same as the swingarm. I have a motion pro bearing driving kit that greatly helps pressing them into place!

Have the hotfootmoto chain sliders, as well as the manifold and airbox boots, I'm waiting on a few fastbers to put those on. Aside from mounting tires, the build is stalled as I wait for parts.

Thanks for the info.

I like the FMF universal. Any issues on mounting it?

KDXGarage wrote: ↑02:31 pm Jun 05 2022 Thanks for the info.

I like the FMF universal. Any issues on mounting it?

No issues, you need a long M6 bolt for mounting and to loosen the exhuast braket that mounts to the frame. It did get scratched during the install, there is no clamp liner.

time to cut up an old bicycle inner tube :-)

All done! Needed a full rebuild. Crank seals were shot, woodruff key sheared. Got a new flywheel and stator. I advanced the timing slightly, gobs of top end power. It can be lugged around in low gears too.

HECK YEAH! Congratulations on getting it all done. Enjoy it. It looks great.