250r to 300ex to 350x

[chris46250r]

I found a rolling chassis 250r that was converted to have a 300ex motor. The guy threw a chain and busted to motor and offered to sell me the thing minus the motor for $800. My question is how hard would it be to put a 350x motor on it? Seems like back in the day some people were putting the 350x motors on 250x's and 300ex's and it seemed like an easy swap. I already have a running 350x that I ride ever now and then so if this was an easy swap I could have a cheap fourwheeler or dang near free one if I put the rest of the 350x on e-bay.

[250Renvy]

I've heard the 350X motors have quite a lot of power, but why not put another 300ex motor back in and build it to a 330 that way you have electric start and reverse and 300ex parts are in plenty supply.

However if you want to put a 350X motor in, take pics and contact Rocky ridge racing, they used to do that mod all the time. I'm sure there'll be some cutting and fabricating involved because it was already modified for the 300ex motor. Otherwise I don't think it was major surgery for the 250R mounts. There is actually a 350X modded frame on ebay right now. You could just swap the frames.

http://cgi.ebay.com/ebaymotors/250r-350x-modified-frame_W0QQitemZ250071511890QQihZ015QQcategoryZ4398 1QQrdZ1QQcmdZViewItem

[chris46250r]

The reason to not put a 300 motor back in it is because I already have the 350x motor. I already have 4 fourwheelers and dont really need any more, just thought if it was fairly easy and only $800 for the roller I would do it.

[Slinky]

Originally posted by 250Renvy
I've heard the 350X motors have quite a lot of power, but why not put another 300ex motor back in and build it to a 330 that way you have electric start and reverse and 300ex parts are in plenty supply.

However if you want to put a 350X motor in, take pics and contact Rocky ridge racing, they used to do that mod all the time. I'm sure there'll be some cutting and fabricating involved because it was already modified for the 300ex motor. Otherwise I don't think it was major surgery for the 250R mounts. There is actually a 350X modded frame on ebay right now. You could just swap the frames.

http://cgi.ebay.com/ebaymotors/250r-350x-modified-frame_W0QQitemZ250071511890QQihZ015QQcategoryZ4398 1QQrdZ1QQcmdZViewItem
that frame doesnt even come with the motormounts needed....it would take more fabrication than just putting it in. The 350x motor might be taller than the 300ex motor. but it might not be a bad thing to try and swap. Thats a good price on that roller....to fit a 350x motor in one of those frames the lower frame rails need to be widened and the top right frame tube needs to be notched (to clear the oil lines) the motor must sit down in the frame in order for the sprockets to be in the right location.

[rbm300ex]

go 250!!!!!!!!!!!!!!!!!!!!!!!!!!!:macho :)

[SWIGIN]

if you got the 300ex mounts the 350x will bolt right in with one mount change.

the upper rear mount will need to be changed or you can just cut the case down...heres a pic of my 350rx

[GT300]

Can you post some detailed pics of the frame with the 300ex mounts? My friend is in the works of fitting a 300ex motor in a 250r frame. This would be perfect.

Thanks