Well I just got done jetting my z400, got the air/fuel are 3 1/2 turns. I used the dynojet stage 2 kit... with a 155 jet and the needle set at 3rd level. I have a Yoshimura RS-3 Exhaust with stock filter with no snorkel and no lid. It runs great, until I seen that the head was red hot?!?!?!

Can anyone give me some pointer to where im going wrong?

 

With the work you just mentioned sounds like your running lean or if the timing could have changed it is retarded too far. Did the header turn red while running part throttle, idle or WOT

 

My buddy has the same set up and had the same prob ended up with a165 jet

 

You're running too lean. I'm running a 165 w/no lid and full wb exhaust.

 

Yes my friend you are running lean. Goto 165 like Quadnoob said, but once you get a better air filter you are going to have to jet up agian. Also are you running that exhaust with the silencer in?

 

iam also running a 165 main jet...

 

I run a 175.