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Fitting a 300R cyl on an older 250R

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Hello everyone!

I'm in need of some tech advise about a project for my brother's bike.

It's a '96 KLX250R which he's gonna rebuild from the bottom up.

We want to put a 300 cyl kit on it, but I could not find anyone who can

confirm that the 300 cyl fits right on with the 250R cases and head. I know

the parts # are different, but so is the case with the 250S (from '06) - which

seems to fit right on. The 250S seems almost the same as the older 250R, but then again...we don't want to purchase parts and end up :) - as I said, it's gonna be a full project, in and out.

Any sure info about it will help greatly- and hopefully we'll be able to upload the whole documented project. Thanks!

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The 300 cylinder will not directly fit on the 94-96 KLX 250's. A riding buddy of mine with a 96 got his from Jerry at FSW. He had a 331 done out of a 300 cylinder. I believe Jerry turned down the cylinder to fit the cases. I would think any good machine shop would also be able to make it fit.

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The 300 cylinder will not directly fit on the 94-96 KLX 250's. A riding buddy of mine with a 96 got his from Jerry at FSW. He had a 331 done out of a 300 cylinder. I believe Jerry turned down the cylinder to fit the cases. I would think any good machine shop would also be able to make it fit.

+1.

The 300R cylinder will not directly bolt-on to the 250R case. The opening in the case is too small to accept the cylinder skirt.

I've seen people get around this by splitting the case and having the opening machined. I'm not a big fan of removing material from the cylinder skirt, but if Jerry did it maybe it's OK. It would certainly be more simple.

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Thanks allot guys!!!:thumbsup:

Me and my brother have to debate about a bit more, but by your help it

seems the 300 it is (who knows...maybe we'll go for a 331 kit:thinking: ).

Will record the whole thing, and update as soon as I can.

This is how the little Mean Grean looked right before it got it's engine "smacked"

dsc01925p.jpg

Now it starts to look more like this...

14032009004g.jpg

:usa: and by the time we'll end up with it...well, we'll get to that soon!

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