build Qs

[hondadude101]

Hey guys im doing another 400 rebuild, going with 426 11:1 wiseco, stage 2 hotcam and a full yosi exhaust, im wondering what jetting to run in the carb, seems like when i jetted my old 400 all it did was suck more gas, so I dont want to go to big, its not gonna be an mx bike, 2nd Q is should i be putting HD head studs in the bike? iv had trouble on high compression 400s with blowing head gaskets, but stock bore 450s have held for me as long as the head wasnt warped. thanks for any info

[426kidz]

I cant recall what jets I ran, I just upgraded too a 450 carb, I would skip the 400 carb and go right too a 450 carb, I did get the GT thunder studs and have had no problems. I would also get a crf timing chain just for insurance. The main thing is to do it right the first time so you dont have to go thru it again. ZRpilot makes a nice adaptor for the 450 carb so it fits well. Cometic gaskets are the best gaskets to use also. wiseco piston, stage 2 cam...

[CJM]

Do the studs, its worth the extra coin just incase.

170-175 main approx

[426kidz]

I have the same build on my bike, I can check tomorrow and see the exact jets I run... it ran perfect BUTT i still say skip this and get a 450

[hondadude101]

its kind of being done on a budget i already have 800 just in parts with the exhaust and getting the cylinder machined, im going to give the stock studs a shot and the kid said we can tear i back down his summer when he has more money if it leaks again, should i not change the pilot jet?

[Stickman400]

If ur gunna run the stock 400 carb. just put in a 42 pilot if u haven't already and it'll be good to go with that pilot.

[riley1374]

I have a similar set up, but mine is a 406ex jetted at sea level, 11:1, stage 2 cam, whitebros full exhaust, and lid off. For winter so far 45 pilot, needle moved one richer, and 180 main. Runs like a raped ape.

[hondadude101]

well i thought i had a full system, turns out its a modified stock header and the guy wont own up to selling me a slip on, keeps saying its a full system but the header is stock and not much i can do about it so what jets for a slip on pipe with the same motor setup

[CJM]

Full system really doesnt even help this much b/c the stock header design really cant be improved upon all that much.