99 kx 250 crankcase compatibility

[subliminaltrips]

I have a small crack in my cases, both left and right. Im trying to source a good set on eBay and I'm finding that people are listing 98-01 as compatible with all the 99 internals, any insight or anyone possibly have some cases laying around, a lot of the ones on eBay look to have flaws. Ill get some pics later on, but I'm debating on having them welded and grinding and filing them back to a flat mating surface to save money, but there is a deal on a 98 and an 01 case set on eBay and i might go ahead and get them if they will fit and try maybe fix and keep the ones i have now as a spare. any info is appreciated. I'm no noob with bikes and mechanics, just got this kawi in pieces for almost free and wanna get it going.

[sandblaster]

According to one of our Guru members, 92-04 WILL interchange
However, 97-04 USE A LARGER SHIFT FORK PIN & 1 LESS CASE BOLT
I don't have any but others here may..

[subliminaltrips]

cool, thanks for the reassurance, i have heard the same thing or similar, but wasn't exactly sure.

[long_av8r]

According to one of our Guru members, 92-04 WILL interchange
However, 97-04 USE A LARGER SHIFT FORK PIN & 1 LESS CASE BOLT
I don't have any but others here may..

Old thread, I know, but I did a search and this is what came up.  I just picked up an 04 250 with a ginormous hole under where the tranny is.  Both sides of the case blown out, broken gear, and basically thrashed beyond help.  I have a spare engine for my 98 that I was thinking about putting in the 04 frame, but from what I read here, I can use a spare set of 98 cases and put all of the 04 internals in it and have an 04 to add to the 89 and 98 I have.  The 04 top and bottom end are perfect if you can believe that.  Not sure what happened to this thing to blow the tranny through the cases.

So, my question is, what's the better way, put the 98 engine in the 04 frame and run it, or put all the 04 internals into a spare set of 98 cases and run it as an quasi-04?  Not sure on the condition of the tranny yet, but if its rebuildable, then that's what I'll do, unless the 98 is that much better of an engine.  Thoughts?

[umberto]

From what I’ve heard, the 98 engine will be harder hitting than the 04. If you want a really solid woods motor, I would go with the 04/98 hybrid. If you’re more desert and motocross, then the 98 would be better.

[long_av8r]

Thank you umberto, that was exactly the answer I was looking for.  Now I can set up one for MX and the other for desert and I'm covered.  I had thoughts of making an AF with the spare engine and even have the frame, but lack everything else., so this makes it pretty easy.  An 04 for $350, plus the cost of the spare engine, another $350, and I still have the 04 top end and crank on the side.  Gotta love OfferUp!

[sandblaster]

Jason at JT Engine Works, Steve Parris (With Turbo Cranks), and myself (KX Guru Racing) are working on a 1998 KX250 rebuild.
The intent is to find out if the Turbo crank can be made to work and if so, what kind and how much power does it make..



We should have dyno results in about 2 weeks.

http://www.oem-cycle.com/forum/viewtopic.php?f=41&t=1436

[long_av8r]

Thanks Sandblaster, that sounds interesting, I would like to hear how that works out.  I'm also researching a 295 option.  I've always had great results from Eric Gorr with my 500's I've had in the past.  Is he still putting out good work?