sorry! HELP with jetting plz

[bigmikey119]

Ok to start off I live in michigan 406 tc cam tc port and polish powerboamb header hmf pipe Whats A good starting point?? thanks guy for all the help and sorry to ask about jetting I know its been beat to death!

[400exrider707]

Filter? Lid on or off? Makes a huge difference.

[bigmikey119]

off and on if you can say just to give me a idea what the diff is! thanks

[CarGuy7a]

with the lid off it sucks in more air in which you may need a larger main jet to compensate for the air fuel mixture.

[bigmikey119]

thanks I am really looking for a good starting point. 178main to big? niddle on 4 notch down?? 42 pilot?

[bigmikey119]

I would also like to add it been 75-85 here

[CarGuy7a]

what kind of jets do you have keihin or dyno jet?

[bigmikey119]

keihin

[Wheelie]

If you are using Keihin jets w/ the lid off:

40 or 42 pilot, clip down one notch from stock. 162-165 main.

[bigmikey119]

so A 178 is way too fat! thanks

[Wheelie]

IMO-yes a 178 is WAY too fat.

FYI--I'm running a 175 in my 440 stroker.