Dropping a bigger engine into XT125X

Hey all,

I’ve got myself an XT125X, brilliant lil SuperMoto bike… but the engine is sadly lacking a bit :blink: I was thinking about getting my hands on a Yamaha YZF250F engine and dropping it into the frame.

Just want abit of advice on doing something like this, like things to look out for, problems I could have, etc… plus if the LB Church thinks it’s a good idea!!! :wink:



Wouldn’t it be cheaper/easier to buy a larger bike (e.g. DRZ SM), or a 250 enduro bike and convert it?

I’m no mechanic or anything, so I could be completely wrong.

cbt only?

Chain on the same side is the big one and does it fit in the frame (obv ull need diff mounts)

you can put most engines in any frames, hard works getting it mounted right for chain clearance in swingarm etc and alignment, we have built loads sv650 in a moto, kx500 in a kx80 and more, do it proper though as a kiddie dide on vd after converting a 50 into a 500 sad times :frowning: plus a guy i know built a 660 engine ina little bike and it looked good weld was sweet but engine sat too low in frame and after 15 test miles the chain ate the swingarm away, left unoticed would of got nasty:w00t:

anything is possible mate but would have a quicker engine but crud brakes and suspention. get some mx tyres on it and enjoy it off road:)