250r engine if 400ex frame

[tlcracing]

just wondering if anyone has seen a 250r motor in a 400ex frame i know servicehonda sells it but would it be hard thanks

[wilkin250r]

Service Honda sells the dirtbike CR250 engine in a 400EX frame. Not quite the same as the TRX250R engine.

I've seen someone on here do the conversion before.

[Dave83]

There was one running at our track last year.The only thing I saw wrong was the guy didnt take time to mount an adequate radiator in it and it constantly overheated.Another guy bought the frame and put a YZF400 in it with a stock R radiator.Worked out good this way,if the other guy would have used the R radiator it would have been a pretty sweet bike.

[elchankoblanko]

This might sound like a stupid question but does the cr250 dirtbike, or anybike for that matter, have a couterbalencer?

[tlcracing]

so a 250r engine should be able to mount up because i'am still not sure if i want a 250r or a 450 conversion quad thats why i'am asking because i know the 450motors mount just not positive if a r engine will fit the ex frame

[TheFontMaster]

I would say to stay away from putting a 250r motor in a 400ex frame, the 250r's handle better anyways.

[Dave83]

The R engine is much smaller than the 4 strokes,so if the 4 stroke fits,the R motor will have more than enough space.The EX frame is real close to R geometery(basically the same front end),the bigger4 stroke motor caused most of the handling descrepancies between the 2,IMO.If you go with the R motor,take some measurements from an actual R and try to set your motor in your frame like the R.Good motor placement = good balance.

[crazyracer250r]

my friend andy has one he does all that fabricatrion stuff and his is bad ***** the the hardest part he said was somethin with the carbourator and airbox

[WheelerBob]

Check out the June atv action, The service honda 250r conversion is on the cover. They tested it and said it is a beast, according to the article the service honda 250r with the stock CR250R motor with no significant motor modd's make's a yfz 450 seam slow, now according to the article you can order the complete quad for $8999, sound's like a deal to me, if anyone has one of these please post back with review's. I read the original dirtwheel's test of the 250r in 1986 and they said honda had to detune the CR250R motor slightly by lowering the compression to keep it from overheating, if this version is as advertised a highly tuned or to be more accurate not detuned in any way, it must be totally wicked. :D :D :D :D