Biggest motor that will fit in 300ex frame

Hello everyone, first post. I am a big bluetraxx member and come over here just as much but just now have had time to register. I have a 95 300 ex that I would love to make faster and that motor just wont cut it. What have you guys worked with in the past/present? I would love to put a CR250 motor in or a XR650.

if your good with making stuff you cut shove bascally (sp?) any motor in, by making motor mounts and stuff. the hard thing is that the frame was made for the 300ex's power. increasing the power by putting a stronger engine in comes along with other mods. you would need a longer swingarm, aarms to the quad can handle all the power, frame reinforments(guessets), and good life insurance:D

[exriderdude]

you can put a 350x motor in it

[K_Fulk]

Ive seen a couple 4ooex motors too. But you can do all out more with the 350x mod wise.

[DEAL]

The 300ex motor barley fits!

[R-Crazy]

sorry for the stupid question, but what are gussets?

dave

[R-Crazy]

i think i got it. guessets are bars to go in the cormers and such to reinforce the frame. correct me if i am wrong; but why would you need them with a stronger engine.

dave

[Rastus]

Because you have to , to keep the motor from riping the frame apart. But, i havent really seen a 300EX's frame bent, have you guys ever see it happen?Anyway, with all that extra power, theres alot more stress on all the parts, etc.
Preferably,use a motor with a counter-balancer to keep it from shaking your teeth out.