Plume of Smoke: Weber 38

[fjatheart]

My Dad's Weber 38 just starting acting up. When you crank the Cruiser you have to leave your foot on the accelerator to keep it running. Once you let off the gas a white plume of smoke will puff out of the top of the carb. We can't hear a vaccum leak and we've tried to clean any obstruction from around the strainer. We can't see any idle jets behind the fuel mixture screws. Any idea where to start?? We've been on the Weber website and read the FAQ section over a couple times. Where should we look?

Carb is on a 2F that has been rebuilt with an RV cam over two years ago. Gas tank has been cleaned out over a year ago. This Cruiser is cranked each week and driven. The problem has progressively gotten worse.

 

[mudnyreye]

Have you adjusted the timing in any way? it sounds like a timing issue, rather than a Carb.

 

[fjatheart]

But it runs fine when you give it gas, but you have to keep your foot on the gas pedal. Would the timing slowly change??

 

[mudnyreye]

Yes, the timing changes, depending on the amount of vacuum created by the motor.

 

[fjatheart]

Hmm...explain please

Could you explain how the timing can be changed by the vaccum? Stroner the vaccum the more the timing gets off or what???

We're running at DUI dizzy and that has not been messed with in a couple years.

 

[msapers]

Just a note on the smoke and what it may mean:

White smoke=usually steam=water in the combustion chamber
Black smoke= fuel=rich condition
Blue/light grey smoke=oil=oil in combustion chamber

 

[donny paradise]

Just a note on the smoke and what it may mean:

White smoke=usually steam=water in the combustion chamber
Black smoke= fuel=rich condition
Blue/light grey smoke=oil=oil in combustion chamber

Your diagnostic colors are for out the tail pipe, he posted (white plume of smoke will puff out of the top of the carb)

 

[msapers]

You're right, my mistake. Probably is timing. Beers on me