KDXRIDER.NET

Hi everyone. Not new to motorcycles but new to the KDX. I’ve been looking for one for quite a while and finally found a 1992 250 that looked pretty decent, and was relatively cheap....because it was “seized from sitting.” I figured I take the chance and see if I could free her up since the rest of the bike looked fairly good. I dug in and found the reed valve assembly was gone, the intake looks like mice were actually gnawing on it, and the worst possible scenario... it wasn’t the piston that was seized, the crank is totally rusted stuck. The rest of the bike is in great shape, original plastics no cracks, wheels are good, seats great, I want to save it. Does it look like the motor can be saved and if so, who is the shop to send it to? I could have handled the top end assembly, but this I think is beyond my skill set. I would love to hear your thoughts on whether/how that cylinder can be repaired and if you think the crank can be saved. Hopefully you can get some idea of her sad state from the pics.
Thanks for any input!

You would be surprised what you can get running. My friends dad got an rd350 twin two stroke running that was sitting outside with the heads off for who knows how long. Another friend of mine swamped his brother’s banshee and didn’t probably “clean” all the moisture out of the crankcase and let it sit over the winter. Actually looks like what happened to your bike. Buy a gallon of kroil oil and fill the lower end and let it sit for a month and do it’s magic. I bet you will be able to free the crankshaft and rod fairly easy. Use a breaker bar on the flywheel nut and slowly rotate the crank to free it. Put a piece of pcv pipe over the rod and do the same. Once everything is loosened up you can split the cases and inspect the bearings. Hopefully the transmission didn’t see that moisture.

The previous bikes I mentioned had the top end’s freshened up utilizing the lower ends that were freed up and ran for many many hours.

Welcome to kdxrider.net. When I activated your membership, I was hoping to see some KDX250 pics and sure enough, you hath provided.

Depending on the actual dollar amount that "relatively cheap" means, I think you should be OK, even if you decided to go all out on the rebuild.

I would take the engine out of the frame and flip it upside down, then try to flush it out. After flushing re-evaluate the condition.

What am I missing on the cylinder? thin layer of rat hair??

Besides the engine, the rest looks like you are a step of a normal rebuild.

Thanks for the input! She’s getting fully resurrected! I dropped the motor off at Ken Oconnor Racing in Connecticut this afternoon for a full top to bottom rebuild and porting. Other than rebuilding the forks and brakes and replacing the consumables, most of what’s left to do is just cleaning. I’ll keep you guys updated on the progress! Definitely looking forward to getting her done in time for spring.

Welcome to the forum. Nice to see an old 250 still kicking.

Man why did you do that? I wanted to see if you could of got it running.
Well at least you know it will be solid and reliable with a professional rebuild. Have fun with the rest of the project.

Welcome to the site and good luck with the rebuild. I'm in Vermont about an hour from Albany.

I finished her up a few weeks ago! She turned out better than I could have hoped. I’ve ridden about three hours total on the fresh rebuild and she rips! I’ll be running her in two weeks at the Unadilla MX Rewind hare scramble.

Good job! Sweet

Man, oh man! That looks lovely! Congratulations on getting it all done.

As always, I say "check that chin tension". :-)

I’m sure it runs as good as it looks.

Welcome! I'm not too far from Albany myself. It's nice to see an old kdx get a second chance