new to hybrids, have a few ?'s 400ex

[mineralgrey01gt]

I picked up a 400ex about 2 months ago and have been tinkering with the idea of a lot more power (poor 400 motor isnt cutting it anymore). I see different 400ex builds, such as the yz426 and crf450, etc but I have a few questions. So far this is the knowledge I have aquired for a hybrid build:

different bearings or grinding down the swinger for chain purposes?
different exhaust
radiator mounts
upper and lower engine mounts, and thats all i can think of. Now here are my questions:

Which engine would be the best performer? I do not plan on racing this at all, just mainly messing around the house and some occasional dune trips and such, but i want gobs and gobs of power. I have been leaning towards the CRF450 engine which is a little pricey but i feel it may be worth it in the end.

Does the yz426 perform much better than the 400ex engine?

would it be better for me to find a 400ex/250r frame that is ready for the engine or just tackle it myself?

Besides, carb, wiring harness, carb to airbox boot, exhaust, what else do i need? How are the engines getting oil? Is it like the 400ex where there is a seperate oil tank (which im assuming there is) Where do I need to mount that at. Also i didnt know how to search for this so i just posted it up. Any links will be extremely helpful.

Also i just thought about this, anyone I could send my frame to to have it done? I could probably do it myself which im assuming ill need the motor first to get all the measurements

[yz450hybrid]

If your interested in running the yz motors, i have a very nice 400ex frame that is ready to go, all you have to do buy a yz motor and a few small parts and then everything else is 400ex parts.

I have all the difficult thing are done already!!

I have frame/subframe, HMF full exhaust (fits great), aluminum airbox, laeger swingarm, custom aluminum oil tank, boot to carb, plus more..

Let me know if ur interested thanks

Sorry i was not trying to jack your thread...

[mineralgrey01gt]

not highjacking at all lol, how much for the frame, subframe and HMF exhaust oh and the custom aluminum oil tank shipped to 70733?

[250x_kyle]

yz motor takes differnt length bushing then the stock 400ex. the crf requires you to grind the swingarm to align the chain.

for the exhaust you can use a 400ex slip on and just get a header for the motor you put in. but you will have to have a custom mid pipe bent.

radiator mounts are fairly difficult to mount up in the 400ex frame if you try to use a stock 400ex oil tank.

new upper and bottom motor mounts are a must. for the front motor horns you can keep the stock 400ex location but new mounts have to be bent. if i had to do that again i woul have welded two cross bars in and made straight front motor horns. you may also have to notch and gusset back by the shock mount to get a good intake set up.

realy any motor (yz 400, 426, 450f. or crf450f) is a good performer. and yes the yz426f out performs the 400 motor.

as far as tackeling it yourself. that depends on whe welders and tools you can get your hands on. and how much skill you have doing so. if you do buy a frame dont buy a hack job.

besides carb wiring boot, and exhaust and motor. your going to need a good radiator. probably and oversized 250r. and over flow bottle. and just a few random odds and ends.


the crf is a wet sump motor stock. so the oil is housed in the cases. kits are available to do the same for the yz motors. or you can run an external oil tank like on the 400ex. if you used a stock 400ex oiltank it makes fitting treally tight for the radiator. i would reccomend having a custom one made. and it would need mounted somewhere near the stock 400ex location.

i dont know how all converts frames any more. i know jb racing used to and i think hre still does. and yes you need the motor for fitment if you do it yourself.

[mineralgrey01gt]

Originally posted by 250x_kyle
yz motor takes differnt length bushing then the stock 400ex. the crf requires you to grind the swingarm to align the chain.

for the exhaust you can use a 400ex slip on and just get a header for the motor you put in. but you will have to have a custom mid pipe bent.

radiator mounts are fairly difficult to mount up in the 400ex frame if you try to use a stock 400ex oil tank.

new upper and bottom motor mounts are a must. for the front motor horns you can keep the stock 400ex location but new mounts have to be bent. if i had to do that again i woul have welded two cross bars in and made straight front motor horns. you may also have to notch and gusset back by the shock mount to get a good intake set up.

realy any motor (yz 400, 426, 450f. or crf450f) is a good performer. and yes the yz426f out performs the 400 motor.

as far as tackeling it yourself. that depends on whe welders and tools you can get your hands on. and how much skill you have doing so. if you do buy a frame dont buy a hack job.

besides carb wiring boot, and exhaust and motor. your going to need a good radiator. probably and oversized 250r. and over flow bottle. and just a few random odds and ends.


the crf is a wet sump motor stock. so the oil is housed in the cases. kits are available to do the same for the yz motors. or you can run an external oil tank like on the 400ex. if you used a stock 400ex oiltank it makes fitting treally tight for the radiator. i would reccomend having a custom one made. and it would need mounted somewhere near the stock 400ex location.

i dont know how all converts frames any more. i know jb racing used to and i think hre still does. and yes you need the motor for fitment if you do it yourself.

that helped a ton. I have a stock 250r radiator that i was going to use but i can get an oversized one when the time comes. Does anyone have any pics of the oil tank setup on the 400ex frame?

I have a friend that is a damn good welder and me and my bro can make all the parts, measurements, etc to make it work I believe. Im considering just buying a frame done already and swapping everything from my 400ex to it.

Ok now when you say front motor horns? Does that mean the front motor mount? Im confused as to when you say this.

[yz450hybrid]

pmed ya

[ss440ex]

I have a set of the front engine horns left over.....

Pm me if interested.

if you go with a crf450 like i did here is a very big help

http://www.exriders.com/vbb/showthread.php?s=&threadid=90605&perpage=10&highlight=400ex conversion&pagenumber=1

[mineralgrey01gt]

damn thats a lot of work and im not sure if i wanna cut up my frame quite that much. I might try to find a different frame and go from there. It doesnt seem to hard though, hell if I get bored one weekend ill tackle it

for all the motors and to notch my frame and rad mounts took me about 2 hours and a tig welder

[markvette]

i have a custom built oil tank and air box built by ss400ex for a ex/yz hybrid. about all i have left from my part out.

Mark

[250x_kyle]

Originally posted by mineralgrey01gt
It doesnt seem to hard though, hell if I get bored one weekend ill tackle it

hard not. time consuming yes. i told myself if i worked on mine for a weekend i would have it done as well. had about twenty hours of time invested in mine and wasnt satisfied at all, but i was also pushed for time and welded up a few other things for people in the mean time. id like to do a crf 400ex conversion but i would have to get my hands on a tig welder to do another conversion.