Can I put a 250 2stroke motor on a 125 frame

[2strokefan]

Basically I have a 2006 yz 125 that keeps breaking down, most of the time it is the clutch no its the piston. So I have decided to put in a new motor, I would like to put a 250 two stroke motor onto my 125 frame. Anyone know if this can be done.
Thanks
Ryan

[ktm_cody_199]

As far as I know the frame is the same,but as for your ignition,carb,and motor mounts you will need to replace your pipe.Check your dealer about your ignition and stuff.

[mephistopheles]

I have a 2003 yz125 and happened to have a beat up 2003 yz25 frame in the garage. I just went in and put a 125 engine in the frame to see if it would fit and it is not even close. I don't know if the changes made to the 2006 make a difference or not, but the older bikes do not swap. you can get a frame off ebay for a couple hundred though and swap everything else.

you would need a frame and carb but I think everything else is an evenswap

[racerfty]

I checked the yamaha parts system for 2006 yz 125 and 06 250 the part numbers are different (125 5151099-001 and 250 5152209-001) This normally means something is different, dont know what but being it is a race bike and every once counts i am sure they would not build a frame to handle the under powered 125 and the powerful 250 to the same specs. But on the other hand i have see a 05 blaster with a 76 yamaha 400 bike motor in it, if there is a will there is a way, just with the alum frame, you can't use a torch to cut, or a normal welder to "correct" the frame if new mounts are needed.

[dklassen]

I didn't think that late model YZ125's were unreliable. Yes, the top end needs replacement however if you do frequent maintenance and install a Hinson or similar clutch you should be able to ride the bike for quite a while between rebuilds. A 250 motor is the NOT answer to your problems.

[Aus_Rider_22]

Originally Posted by dklassen

I didn't think that late model YZ125's were unreliable. Yes, the top end needs replacement however if you do frequent maintenance and install a Hinson or similar clutch you should be able to ride the bike for quite a while between rebuilds. A 250 motor is the NOT answer to your problems.

dklassen is on the money a 250 will give you problems as well unless you keep up basic maintenance. What exactly are the piston problems?