1990 yfm350ER motor swap.

[Jlg9969]

Does anyone have any recommendations on an engine to place into this Frame? I mean besides the OEM standard.

[JoeB]

Just posting for the follow this thread. My 350 is down on power to its 225 sibling

[Gwbarm]

This should be an interesting project, which bike is it , Big Bear, Moto4.

[Jlg9969]

Well mine is currently a Moto-4 but I am wanting to see what choices of motors I can possibly fit into this frame without a whole lot of fuss and welding. 

[Gwbarm]

My first thought would be a Big Bear 350 engine, if you can find one about the same year as yours it might come closer to fitting without much modification, just a thought. I have never done it.