Should I mess with recently rebuilt carb??

[scb1712]

Hi all,

I had the carb rebuilt on my Volvo penta 3.0l two years ago to cure a few fuel related issues. The engine has always run rich since having it done, and this year I've noticed a lot of smoke at idle, black soot on the transom and unburned gas bubbling up from the exhaust when it's shut off. The question is should I mess with the mixture screws to lean it out a bit, of leave well enough alone. Other than the issues above, the engine runs and performs well.

Thanks,

Steve

 

[bruceb58]

I would adjust the idle mixture.

Just so you know, adjusting the idle mixture basically does nothing to the mixture when you are running above idle but sounds like only idle is your problem.

What do you mean by gas bubbling up from exhaust?

 

[scb1712]

What I'm referring to by the gas bubbling up, is that when I shut the motor off (particularly when it isn't fully up to temp) I get little droplets of gas that float up from the exhaust and evaporate when the reach the surface of the water. But you can see the little rainbow coloured rings before they fully evaporate.

 

[bruceb58]

But you can see the little rainbow coloured rings before they fully evaporate.

That actually kinda sounds beautiful...sure you want to fix that?

What is your choke doing during this time, it coming off early enough?