Oct 9, 2007
hi there, i have a 2001 yz125 which is road legal but i know that the engine wont last 5 minutes with me riding it on the road everyday also its not really suited for riding on the road as its one of those bikes where the throttle is all or nothing!!! so, now i know this is going to sound like a total waste of a yz but, i was wondering how hard would it be to fit a yamaha dt 125 engine in it, i know its a dumb i idea but i have to ride on road as much as i do off road mainly to get to the off road spots and this way i could ride my bike on the road all day long no probs but still have a way better looking bike than my mates with there dt's and kmx's i have looked into it and i could get an engine from an 04 dt 125 fairly cheap, i would have to get an exhaust made up to fit the yz frame, a 2 stroke oil tank, maybe made up some engine mounts etc what do you think


Thinks he can ride
Dec 2, 2001
Sounds like a good idea. It should be feasible if you have some welding/fabricating experience.


Feb 10, 2007
Not sure how you got a YZ street legal...but I'm not asking. :think:

Try adding a flywheel weight to the thing. That will calm it down. I think Steahly has them in 6, 9 and 11 ounce weights.

Try jetting it properly. That will also help throttle response.

Try a pipe tuned for low end.

Different gearing.


Lot's of ways to make a 125 more rideable. might be better to get a bigger bike for what you want to do. I spent a lot of time in my younger days riding small bore bikes lots of miles to get to a riding area. A 250 is a lot more comfortable than a 125 for long distances.

I guess it all depends on what you really want.


Top Bottom