400ex/250r info needed

[j450rking]

i'm thinging of doing a 250r/400ex hybrid with a ex frame and a 250r engine. what do i need to do to make the 250r engine fit in the ex frame and what engine should i get? also can i use the stock ex swing arm?

[250Renvy]

IMO this is a terrible hybrid idea. Just sell the 400ex and buy a 250R.

The idea of a hybrid is to put a bigger motor in a better chassis, or 4-stroke in a 250R chassis or bigger motor in whatever chassis you have.

Putting a 250R motor in a 400ex will make it faster, but it won't handle as good as a 250R and will likely devalue your 400ex.

[NeverLiftRacing]

i think its a great idea. seeing as how its a hassle to find any 250r parts and a zip to find any 400ex parts i think it makes sense. i want to see this thing when its done!

[j450rking]

well my ex is fully built so it handles great and i like how it's setup but i want it faster and lighter so i came up with the idea of doing the r/ex hybrid. this would be my first hybrid and i don't think it would be that hard (but i could be wrong) and i know it has been done with cr250 engines and they are faster then hell. service honda actualy builds them so i figure i could do it. my biggest thing is i really don't want to do any frame cutting b/c i want to be able to keep my ex engine and put it back in if i wanted to change it back. i don't know andthing about 250r engines other then they are fast and smaller then the ex engine and i if i can remember right about 30lb less. and then i would be taking away the battery and the oil tank and cooler and some other stuff so i think i could drop a good 40lb off my ex by doing the r/ex hybrid. and the les whieght i have the better it will handle and the better it will fly in the air. if i can get a engine for a good price i will do this hybride and i'll do a full right up on it so others can do it and if i can do it without hacking my frame i will make some extra motor mounts to sell maybe.


from what i can tell from looking at pictures of the r engine i can make it work with just custom motor mounts.

but what i really need first is some specs on the size of the r engine so i can check my frame and see if it will work.

[NeverLiftRacing]

well there used to be a cannondale moto 440 on here with a cr250r motor in it. you should try to find it and see if that user is still active on here.

[j450rking]

i don't think that will help me.