atv with dirt bike engine

[pitcrew]

i have a question..... is the rumors true do dirt bike engines really vibrate to where u have to make new motor mounts after a few races??? ive heard some rumors. i have a gasgas atv that needs a motor and i was thinking about a dirt bike 450... let me know what i need to know so i dont waste my time.

[pro-rider46]

the 450 engines are balanced so itll be good to go

[ALAMX37]

Not at all, my CRf hybrid vibrates less than all three of my YFZ's.

[deathman53]

most of the dirtbike 2 stroke motors aren't counter-balanced. Not all atv motors are counter-balanced anyway, banshee, 84-87 tecate 3, tri-z 250 and I think the small bore yamaha 2 strokes. The 4 strokes all are counter-balanced. Lot of people that put cr500 motors in there trikes, didn't feel an difference, quads are vibaration city.

[pitcrew]

thanks i really didnt know what to do but now i think i made up my mind about the motor. if anyone else has any insights to this it would be greatly appreciated.

[wilkin250r]

Originally posted by deathman53
Not all atv motors are counter-balanced anyway, banshee,

The banshee doesn't need a counter-balance. It's a twin cylinder, they naturally balance each other. It's not off-balance, therefore it doesn't need to be countered.

[CannondaleRider]

Originally posted by wilkin250r
The banshee doesn't need a counter-balance. It's a twin cylinder, they naturally balance each other. It's not off-balance, therefore it doesn't need to be countered.


Yeeep.....beat me to it.

[54warrior]

A friend installed a 98 CR250 motor in his TRX250R frame awhile back. He couldn't stop that thing from cracking the motor mounts and frame, even with 1/2" steel plate for the motor mounts!!! Beef up the motor mounts and the frame would crack, beef up the frame and the motor mounts would crack. Eventually, he sold the motor to a micro-sprint guy and scrapped the frame completely. I have pictures of it somewhere, I'll have to find them and scan 'em in.

[deathman53]

its funny, put that same cr250 motor in a atc250r, you will hardly notice a difference in vibration, no broken frames/motor mounts. Its all about how the forks cancel out the vibration.

[pitcrew]

yeah see i heard that about every two or three race i would have to make new motor mounts becase of the vibrations thats what i dont want i want to install a motor and be done with it.

[deathman53]

You want a dirtbike 4 stroke motor then. Honestly, you probably are better off buying a used trx450r, do some simple mods to motor and it will make the same hp as the dirtbike motor.