z400 jetting question....

[vpofthedrc]

I'm posting this for a friend of mine who just but a new HMF slip on. They told him to put in a 135 main jet, and turn the air/fuel screw all the way in, and then back it out 1 turn.

We did all that, and ran it for about 15 minutes, and the header was glowing orange. My experience with race cars, makes me think that it is too lean, is that correct?

If so, what jet should he try, and is the fuel screw in too much?

Thanks for the help.

[shorgasm]

1 turn out is lean for sure...try 2 out from lightly seated.Go from there.If not you gonna have to up the idle jet.The main seems a bit lean too.I would think a 140 would be better.Filter?..Lid?..sea level? air temp?...lots of variables you need to answer 1st.You might be able to shim the needle with an appropriate shim of you have them.The mid is gonna be lean too until you do.

[vpofthedrc]

I believe he has a K&N filter with stock airbox and lid. No exotic elevation problems, and the air temperature varies alot in these parts. In the low 50s today.

You think fattening it up to a 140 and backing the mixture screw out another turn will help out?

This is a trail bike only, so it doesn't haven't to be exact.

[was123]

Originally posted by vpofthedrc
I believe he has a K&N filter with stock airbox and lid. No exotic elevation problems, and the air temperature varies alot in these parts. In the low 50s today.

You think fattening it up to a 140 and backing the mixture screw out another turn will help out?

This is a trail bike only, so it doesn't haven't to be exact.

yes i would suggest backing the screw and trying a 140..

that will prolly get you about right...

[shorgasm]

140 main
2 1/4 turns out from seated
3mm shim under the needle.

Try that.......if not right on it should be close..