Dilema with Volvo Penta 3.0

[scb1712]

After having issues with the carb for a couple of seasons (issues with the high speed jets etc.) I finally had the carb rebuilt last year. Now the boat runs great, but I get a lot of black residue on the transom which suggests to me it might be running a bit rich. The manual says not to adjust the carb from the factory settings, but I'm wondering if I should lean it out a bit and risk other issues, or just put up with the black residue. Opinions?

If I do adjust the mixture to lean it out, how do I know when I've got it right?

Thanks!

 

[Maclin]

Sounds like maybe a slightly too rich idle and the exhaust out the idle relief ports at the bottom of the transom shield (or a torn or non-existent exhaust bellows) is sooting up the transom. If it idles ok for long periods of time without fouling the sparkplugs and runs out good then I would lean towards putting up with it if you are not used to adjusting carbs

 

[scb1712]

Thanks for the info. I don't think there are any tears in the exhaust bellows, but I'll double check. I'll also check the condition of the plugs to see how clean they are. Otherwise it does seem to both idle well and run well. I've adjusted carbs on cars before, but never on a marine set up.

 

[bruceb58]

If its running well , I would just leave it. Every boat I have ever owned gets a little bit of soot buildup because the run very rich when cold and the choke closed.