yz426 into modified 400ex frame

[mad motocrosser]

I currently have a 400ex frame modified for yz426f motor. I have motor on the way and looking for problems I may encounter before starting. I know this has probably been posted before but looking if anyone can help me out on this. Thanks.

[bulkdriverlp]

i have no clue whatever that motor is looks like for one, with this being ur first post if ya could figure out how to put up a couple pics that would be helpful. go back to ur user cp and put in a area of mi cause i live in upper michigan too.

Wow, way to be an ***. He doesnt have the motor yet so he cant put up pics.

Are there any mods done to the motor? What year is it?

[bulkdriverlp]

maybe i typed it in a way for it to be questionable. you must have read into it wrong!! MY BAD i didnt mean to be an *** at all. im not like that. look up all my other post if ya dont believe me. take some downers ur too excited....

[416exmx]

You will need a good intake system from the airbox to the carb. Making the exhaust will prob be the hardest. If your frame is already converted and had radiator mounts and everything, mounting the motor and stuff ought to be pretty easy. Kick start extention will be required also.

[SRH]

go to www.thumpertalk.com its the best place to learn about the motors, the 01 yz 426 had problems with a pin coming out of the shift drum and destroying the tranny i use to have prt # for the updated one... if i was you id get a yz450f motor i think they bolt in the same, also youll need a sleeve for the motor so the stock pivot bolt will fit..not positiive if you have to mill the swingarm down or not, and make sure you have a mount for the headstay or that motor will rip itself out of the frame, youll also need a kick starter shaft extension you can get from east coast atv...not positive but i think you could also use a yz 400 motor....i dont t hink the mounts changed on the motors... oh by the way a guy i know built ghis own chassis for yzf/crf etc and he bought and fmf ti4 system but not the mid pipe and made his own mid pipe so theyd match up, check it out www.race-co.com

[mad motocrosser]

I guess I should have listed question a little better, first parts I have are modified ex frame, yz426f motor, kick start extension, and radiator. Things I know I have left to get are electrical, head pipe, and design intake from carb to airbox.
Now here is where I am at on questions, looking how others had made intake. I will have a better idea once putting together but seeing if anyone who has done this can give me a jump on situation with materials, size, etc. . . I know I need to have oil lines cut and matched to use current 400ex box. Wondering if swingarm will have to be milled for proper chain alignment is the biggie along with axle.
As for motor has head work but looking for compression size. This bike is strickly for mx and looking for gearing with 20 front and 18 rear for both tight and longer tracks. Also looking for anything I might have missed or improvements. Thanks.