450 into 250 frame?

[red85]

I have an 04 KX 250F and I have an opportunity to buy a complete KX 450F engine. Will it fit into my frame? The 450 is an 07 with 15 hrs on it.

[freds4]

No, it will not.

[numroe]

Imagine if it was possible ... that'd be a rather significant change in power output.

[hotnanas]

oh come on now! of course it's possible....just not a bolt on power mod.

[D-K]

Define "fit".

It will not bolt in, but with some measuring, cutting, welding heat treating, and fitting bigger radiators it will "fit".

Get a 450 if you want it´s power. Just because an engine can be purchased doesn´t make it a good deal.

[Pr1malR8gw]

I would have to agree, you will be better off buying a 450f complete bike then trying to retrofit the motor in a 250f frame.