yzf426 in a 250r frame?

[250rmike]

does anyone know if this will work? i may be trading a 250r motor electrics carb and pipe for a yzf motor electrics pipe and carb from my friend(his uncles buying it for real cheap) anyway if i can get this i dont have the money for a aftermarket frame right now so i was wondering if it will fit in my r frame? if not i dont want to have to buy a whole 400ex just to lose money by taking everything off it and putting aftermarket stuff on. thanks alot for any help its really appriciated

[OutlawEX]

Yes a YZF will fit in the R frame..Im currently doing a YZF-400ex conversion right now..It will prolly work better in the R frame ,just beause u got the radiator mounts already there...U will need motor mounts tho

[250rmike]

thank i just wanted to make sure that the r frame was tall enough. if i do get the motor its gonna be a 490 already so i may trade it for a 426 or 440 yzf. 490 is just a tad to much for nationals lol. ill prolly just run the open class until i get enough money to bring it back down to size

[TRX250R87]

I'm guessing the head will hit the gas tank unless you lower the engine in the frame some how!
ERIC

[nastynotchback1]

why does everyone put yz motors in 400ex's in stead of cr 450 motors.is it easier?

[DEAL]

its because the Yzf has been around for a few years now, and its easier to get ahold of a Yzf motor for cheap where as the Crf only came out a year ago or so, so there isn't as many around.
They bolth produce around the same HP and they are bolth reliable motors.
I hope that answers your question.

[Tommy 17]

k&k website has one...

[nastynotchback1]

thanks for the reply.that makes good sense.maybe when i blow up my motor and the warranty is gone i will do a swap like that.sounds fast.

[OutlawEX]

Originally posted by nastynotchback1
why does everyone put yz motors in 400ex's in stead of cr 450 motors.is it easier?

I personally got the YZF motor because it was such a great deal..U dont find a YZF motor for 1k to often,but i know alot of ppl so that was my benfit....From what i have heard the CRF motor is alot of maintainence..If i was to get another upgraded motor it would prolly be the YZF450F just because the YZF's tend to run faster...But then after that u will need to destroke the 450 to a 440cc which sucks..Some ppl think that boring a 426 to a 440 is gonna make it just as good as the 450,but its not...Ya Tim Farr ran a big-bore 440 last year ,but thats tim far,he would win on a blaster...

[nastynotchback1]

why do you have to destroke a 450f.

[sly400ex]

You don't have to, only if you want to race, you have to stay under or at the 440cc limit. Correct???!?!!?!?!

[250rmike]

if i do get the motor i was told that it is a 490 so for a while ill just have to race it in the open class. at budds ill be able to just race it in the 4 stroke class. look out if your racing at budds in the 4-stroke class lol

[nastynotchback1]

i see but i dont race in any class races.i just go to the local tracks and ride and race with a few freinds some time.this is just a winter hobby for me.somthing to do when we are on the winter brake from dragracing.