Webber question

[RMartin]

My 68S runs rough from idle to about 3000 rpm, after that it pulls fine to 7000 rpm. What would cause the idle circuit to run rich? It acts like too much fuel at lower rpm?

[ttweed]

Are you sure it's running rich? Typically, it's more likely to be running lean from a clogged idle circuit or jet. After 3,000 RPM, the mains are kicking in and it gets enough fuel to run right.

Just a guess, but putting a gas analyzer or O2 meter on it will tell you what's happening with the mixture.

TT

[Nitrometano]

Check if the idle jets are clogged. If not, check the exhaust sound of the engine if it sound like shot "rummmmmmm puf puf rummmmmmm" at idle speed. If so, the mixture is rich or the idle jets are to big and try tu use a smaller ones in size.

[RMartin]

I can't say for sure that it is running rich. Just what I thought. Idle is a little rough and when you give it gas slow, it misses until about 3000 rpm. It has been sitting all winter...about 5 months so it would seem likely that something is clogged. There is no backfiring or spitting through the carbs... The idle jets are the originals so I don't think thats a problem.