question about builds

[spec]

I have a 400ex with a blown engine in it right now. But have been wanting a 250r for some time now. If I was to get ahold of a 250r eingine, or a 250 dirtbike engine and swap it into the 400 frame do you think that would work out ok? Or would I be better off fixing the 400 and trying to sell/trade it and get a 250r? Are the 400 frames ok to use with builds like this? Or would the 250r frame preform alot better?

[red_rider38]

I'm starting a 400ex with 2002 yz426f engine hybrid. With a gusset kit the 400ex frame will be even stronger. I wouldn't do a dirtbike 2-stroke engine because of the vibrations. 4-strokes have counterbalancers which help a lot with vibrations. You can also find 400ex enignes in ebay for $500.

[pb_paulie_b]

It's a good plan really. Service Honda sells what they call 250r's. They use the 400ex frame and a CR250 motors. I would do that swap.

[04-450racer]

The vibration from a 250 motor wont be bad enough to notice, if you stepped up to a 500 though you would notice the vibration from those.

[spec]

Ok. yeah I think I might try and get ahold of a 250 and try it out. I've ready a bunch about swapping like a 426 into a 400 frame and all the stuff you have to make for it to fit. Would swapping a 250r engine in there be as much work? Or would it work out alittle better because its all designed for a quad frame? I know theres going to be modifications that are going to have to be made, but was just wondering if its going to be as much as a 426 or no.

[pb_paulie_b]

I'd say only someone who has actually done the swap could tell you for sure. IMO the 250 really isn't that big of motor so that should make it easier. I'd be willing to bet you could get a pipe from Service Honda all
ready to bolt up too.

[born2ride14]

i think 2muchquad made one he said that he had to flip the front mounts ad a few spacers and o mods I THINK