YZ or CRF motor

[mcarlson1]

Im looking at buying or building a hybrid very soon and i was just wanting to know from people that have had both of or either of these motors , which one they like the best? How the reliability is, the powerbands if they wear you out, how hard they are to work on and just the pros and cons of each motor. I cant decide which one to get and am hoping you guys can help me decide which route to go. Any help would be greatly appreciated.

Thanks,
Mike

[usp4u]

this will elicit alotta different opinions....my opinion:
-yzf's: big power, smooth power, ultimate reliability
-crf's: bigger power, harsher power, some reliability issues for some.
ktm's: no expeirience

[250x_kyle]

i have a yz400f motor forsael drop me a pm if your interested.

[mcarlson1]

usp4u thanks for your input i really appreciate it. 250x thanks for letting me know about your motor thats good to know incase i decide to build one. can anybody else help me out? i know you all have opinions of your motors guys! anything is good.

Thanks,
Mike

[250x_kyle]

both motors realy rip its just depends on the previous owners on how well they were maintained. and do you want a sohc or dohc both are two completely opposite set ups with pros and cons. just realy depends on wich brand u prefer i guess.

[speedfoxracing]

go with the yz less maintnece

[250x_kyle]

ive heard the crfs rewquire more valve checks but if the yz motor is out of specs a bit you will kick your heart out for it to start.

[rob-u/21]

I'm currently building an ex/yz450 hybrid. The reason I went with a YZ over a CRF is cause it's supposed to be the easiest engine to fit in to an ex frame, plus I got a pretty good deal on mine. If you decide to go with a YZ engine, I stongly recomend you get an engine mounting kit from ss440ex. He is a member on this forum and fabricates all the hardware you will need to mount YZ 400/426/450 engines into the ex chasis. He has been walking me through on how to mount my motor. To me making the motor align with the rear sprocket is probably the biggest headache so this kit will save you a lot of time. I'm sure others will agree with me.

[fmfhonda250r]

I would get a crf motor, more power and more options for motor parts are avaible. Valves due go bad once in ahwile but compare 65 per vale and there are 4 but when the yz valve goes it's 100 and there is 5 . My old hybrif would take either motor and i liked the way the honda motor felt but thats just me