KX 80 motor questions

[NightBiker07]

Just picked up a 94 KX80 for 500 bucks. new top end. needs chain/sprockets and a front brake caliper/pads. mechanically sound, no frame damage.



now, for the questions.

I know the kx 80/100 used the same bottom end, so what year range KX100 cylinder will fit my 94KX80? would i just need to swap the top end, or does it require a different crank as well?

or, would an even bigger cylinder, such as a 125 cylinder fit? i doubt that though, i think they used a different bottom end.

what are good headpipes to go with the kx100 cylinder? or would a kx80 pipe work?

[atomicsaladbowl]

a kx80 pipe should work fine, and the 125 top will not fit, the 100 from any year should i would think, the same crank should also do just fine, you might be better off just puttin in a whole engine, being that the topend off a kx100 is probably gonna cost close to what the whole engine will, off ebay at least

[NightBiker07]

What would be the best all-around pipe to get for this thing?
i have heard good things about the FMF Fatty pipes.


also, what are warning signs the crank bearings are going out? i have no odd noises or anything now, but for future reference.

[nd4speed]

Pull the connecting rod up and down on the pin and check for movement. Side to side movement is ok. Remove stator cover and pull with force up and down on flywheel and check for movement to test main bearings. Without taking it apart? Good question.