Putting a cr125 or cr250 motor in a 300ex frame.

[Pvt. Maggot]

i just got this idea..i'm thinking more of a 125 because its not as much power but its still alot and its fast so what do you all think. i wanna do it really bad. and if the motor is on the down i can just throw my 300 motor back in and bam so....i think i might give this a try. i need some of you guys opnions on it. let me know what you think thanks.
jake

[Juggalo]

your gonna get a lot of people saying not to do it cuz the motors aren't counterbalanced and it will shake your teeth out. thats true tho. the non counter balanced motor will crack your frame too from the vibration, especially if you do the 250. there are ways of reducing vibration but there will always be too much of it. it would be one hot little quad tho.

[BigThumper33]

how does the vibration affect a quad frame more than a bike frame? My 125 doesn't vibrate at all....

[hondafox440]

I was wondering the same thing. I hear if you rubber mount the engine you will be all set.

[Glow Plug]

You can do it but you would easly be cracking your stock frame even if it were to be rubber mounted. It will vibrate alot more that a cr 125 or any other dirt bike.

[UglyMotha™]

on a dirtbike the vibration is transversed down the forks of the bike i do believe this is the reason a bike will no vibrate, i think that it, i know it got somthing to do with the forks though

[hondafox440]

That makes no sense, because the forks can't take any side-to-side vibration, and plus, wouldnt the front suspension on the quad do the same?

Originally posted by hondafox440
That makes no sense, because the forks can't take any side-to-side vibration, and plus, wouldnt the front suspension on the quad do the same?


its complicated but hes right, the fork tubes absorb the majority of the vibration shocks and forks dont absorb it the same since there not the same, also why put a cr 125 motor in a 300ex frame? the power of a 125 is all in the upper rev range plus it puts out the same numbers as a 400ex but the motor is harder to ride....i could see maybe putting a cr 250 motor in a 400ex frame or 250r but y when you can just buy a 250r

[Pvt. Maggot]

because i like to be different. :o

[UglyMotha™]

Originally posted by hondafox440
That makes no sense, because the forks can't take any side-to-side vibration, and plus, wouldnt the front suspension on the quad do the same?



well there my fellow rocket scientist for starters the motor does not put out any side to side vibrations if you understand how the motor works you will relize that the motor actually puts out front to rear vibrations if you understand this it makes it simpler to understand how the front shocks absorb the vibration of

[Pvt. Maggot]

a 125 should have enough power...should be faster then my stock motor...think it would beat a 400? what all mods do you think would need to be done? welding new motor mounts ect. i think it would be one kickass little bike :devil:

[UglyMotha™]

Originally posted by Pvt. Maggot
a 125 should have enough power...should be faster then my stock motor...think it would beat a 400? what all mods do you think would need to be done? welding new motor mounts ect. i think it would be one kickass little bike :devil:



don't wanna burst your bubble there buckaroo but taking the cr 125 motor out of a two wheeler and putting it in a quad frame will seriously choke down on your hp out put i seriously doubt you'll be able to even hang with a 400ex it will be more in the blaster terroritory if that personally i would keep the 300 motor in it because i think you will be disapointed with the 125, but the 250 would be a whole other story

[Pvt. Maggot]

blasters are faster then my quad :o how do you think my frame would hold up to a 250 motor if i gussetted it? i don't think it would hurt it much...if i put a cr250 motor i would be beating 250rs and 400s no prob because it has more hp then a 250r right? i don't wanna say 50hp but i could be wrong...i'm not sure but i think the cr250 puts out something close to that..fill me in...

the cr 125 puts out 28-30 hp in the bike it will smoke a 400ex , the cr motor is alot faster than a blaster motor , but y put a 125 motor in a quad its not gonan be any fun

[UglyMotha™]

a cr 250 motor would put a serious whoopin on your frame and your teeth but i imagine you could reinforce it, anything is possible when you have a torch and a mig and also again yes the cr250 in the bike frame puts out my ponys than the bike you listed but i don't think your understanding how many ponies you are loosing when you convert it over to a quad, why do you think you bike then would be faster than a 250r when the 250r's motor is a cr250 motor with a counter balancer practically yes the cr 250 has advance since the 80's but don't think your goin to be laying down a whoopin anytime soon


me personally, if i was in your shoes i would take the money you have for this little project of yours and sell you 300 and you'll more than likely have enough money for a used 400ex cause right now there goin for next to nothing, then you'll have this new found power that you looking for plus you won't have to set money asside to get your cavities refilled

[Diedrich]

drop the cr250 and just get an 250r motor. i've seen them in 300ex frames before. it would be pretty fast. heres a pic of one

[Pvt. Maggot]

i have all those pics...i think i sent you them? lol that would work..and no vibe...but 250r motors arn't cheap. ahh maybe a 330 kit would be ok...i wish i could sell it and buy a 400 but its not that simple. so i'll just buy a 330 kit soon. see how that works and go from there.

[toby400ex]

do you have troubles making it up the take off to jumps, if not, get suspension