I have a 2000 Volvo Penta 5.7L GL with 610 hours on it. I keep the boat well maintained and do all the work on it myself.
I was cruising at 3200 RPMs this morning and heard a bang/pop.
Then 2-3 seconds after the initial noise I lost power and the boat began running rough.
I throttled down and looked into the engine compartment and could find nothing wrong.
I throttled back up and I get lots of mis-firing and loss of power. I assume that bang/pop was actually a back fire.
It runs normally under 2000 RPMs and anything over that or 5 gal/hr results in poor running.
I assume this is a carb issue, my fuel is 3 weeks old and I have 3/4 or a tank. This is the first running issue I have ever had with this boat.
I am looking forward to memorial day weekend and I need some ideas on what to check. If I need parts I need to order them ASAP!
Thanks for any help!