HEY GUYS! its me again....just have a quick question...just a question..dont turn it into an aregument. anyways, i was on ebay and i saw this 400EX motor..it was bored out to be a 440EX. it was dont by duncan racing if i remember correctly. they said it was a 2000 dollar job once you supplied the motor....they claimed it produced 50+hp...said it was smoke crf450s and yfz450s with a pipes and jet kits. now here is my question. would a 400EX motor fit on a 300EX frame? with little or not modifications? what alll would i have to do to do that? i mean i know people put 350X motors on the 300EXs but can you stuff a 400EX motor in there? i dont know what its gonna cost to get my motor rebuilt, but if its too much i will just try to find an old 400EX motor to put in it or something. anyways any info would be appreciated....lata![img]i/expressions/face-icon-small-cool.gif[/img]

 

you aint the only one thats curious about a 400ex motor in a 300ex frame.my top end is done for even my valve guides so i want to know too.

 

Im pretty sure it wont without some fabrication because i know that the swing arm bolts into 400ex engine while on the 300ex it is just bolted to the frame. That makes it seem like it wouldnt fit.

 

I think it would just be better to get a 400ex. The handling and geometry are much better and the wieght savings is minimal at best. Just a thought, I wont be the one to tell you not to have fun. A friend of mine put a cbr600 in a blaster, so it wouldnt be the strangest i've seen by a long shot.