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View Full Version : 2002 CRF engine in a 250R frame....what am I up against?


JoePA
04-08-2011, 07:38 AM
Ok I have my 2002 CRF450 Supermoto that sits there int he garage and just begs to be ridden. Yeah it's fun but I feel I will get more enjoyment out of it if I had that engine in a quad!

So my question is what are the issues with putting the CRF engine in the 250R frame? I'm sure it has been done before as this would be pretty much the orignal hybrid? I'm sure trying to wedge that FCR carb in there can be an issue. If anyoen has done it do you have any pics?
250x_kyle
04-08-2011, 08:20 AM
putting a crf motor in a stock trx250r frame in good conditions is frowned won apon due to how rare they seem to be getting. theres a few conversion pics on the forums if you search. if i get around to it i will bring them up. if you dont already have a frame look for a 400ex or an aftermarket frame already built for the motor. but motor mounts getting the carb to fit and aligning the chain. plus gusseting the frame, fabbing an exhaust to fit. getting the tank to fit are all issues.
bikebuilder
04-08-2011, 09:25 AM
go on youtube there is a video of what to do. icant do it know but later today i can send it to here
chopp124
04-08-2011, 09:08 PM
figure out what you think you need for mounts, i have plenty of them from gibson chassis.
C41Xracer
04-09-2011, 09:57 AM
Without lowering the bottom frame rails the top of the engine will interfear with the bottom of the tank also to get the sprockets lined up the top frame rail will hit the valve cover or it will be close. My hybrid is a 250r chassis and the left side lower frame rail was cut out and lowered to make it work
C41Xracer
04-09-2011, 10:12 AM
Without lowering the bottom frame rails the top of the engine will interfear with the bottom of the tank also to get the sprockets lined up the top frame rail will hit the valve cover or it will be close. My hybrid is a 250r chassis and the left side lower frame rail was cut out and lowered to make it work
onall4rs
04-13-2011, 11:43 AM
Ive just finished puting a crf 450 in my 450r had to lower bottom engine mounts made new sleave for swing arm bolt and extend gear and kick shafts but well it