f4istunna
11-05-2007, 12:21 AM
I know jetting post are beat to death but i never really messed w/ carb work much until lately and want to be sure i have a good starting point.
just bought a 400 yesterday has 440kit, cam, fmf ti4 slipon, stock headers, stock airbox w/ uni filter.
It came w/ dynojet stage 1 kit and the main in it is 142 right now, the pilot is 38, and needle is all the way at top slot.
Wouldnt start when i got it, put new plug in and fired up, idles rough then dies if you dont give it gas. If you hold steady throttle around 1/4- 1/2 the rpms vary doesnt hold steady.
I cleaned the carb out good, tried a few diff mains 142, 150, 146 (dynojet)
Was thinking i need to bump the pilit jet up to give it more fuel at idle its 38 now was going to get 40 and 42. But when i do a plug check now its very rich (black and sooty) after just a few seconds running. Also puffs a little black smoke out of exhaust. I checked the plug color just revving in the garage not under load ranging from idle to a few half throttle checks. Was black (whole tip and some threads) after a few seconds either way. Should i go down ont he pilot jet to lean out?
I tired taking the aurbox lid off, still black plug? Im in ohio i think 850ft if it matters its about 45 degrees out avg this week.
Any suggestions what to try
thanks
just bought a 400 yesterday has 440kit, cam, fmf ti4 slipon, stock headers, stock airbox w/ uni filter.
It came w/ dynojet stage 1 kit and the main in it is 142 right now, the pilot is 38, and needle is all the way at top slot.
Wouldnt start when i got it, put new plug in and fired up, idles rough then dies if you dont give it gas. If you hold steady throttle around 1/4- 1/2 the rpms vary doesnt hold steady.
I cleaned the carb out good, tried a few diff mains 142, 150, 146 (dynojet)
Was thinking i need to bump the pilit jet up to give it more fuel at idle its 38 now was going to get 40 and 42. But when i do a plug check now its very rich (black and sooty) after just a few seconds running. Also puffs a little black smoke out of exhaust. I checked the plug color just revving in the garage not under load ranging from idle to a few half throttle checks. Was black (whole tip and some threads) after a few seconds either way. Should i go down ont he pilot jet to lean out?
I tired taking the aurbox lid off, still black plug? Im in ohio i think 850ft if it matters its about 45 degrees out avg this week.
Any suggestions what to try
thanks