Will 1981 yz250 engine fit in a yz465 frame ?

[cleopatrisha]

I have a junk '81 yz465 with good frame and a good '81 yz250 engine.. will engine bolt into 465 frame? if so are there any mods I'd have to make? I am guessing the exhaust port might be a different size diameter.

 

[2 strokes for life]

cleopatrisha, it might it. Also the exhaust like you said would pose a problem.

 

[cleopatrisha]

I looked at a parts diagram with part #'s and compared the 2 bikes. and from motor mounts to exhaust the part numbers match so my guess is the 2 engines are easily swapable.

 

[2 strokes for life]

cleopatrisha, now having looked at it the cases look the same to me almost.