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Ask Dominick Your Own Question
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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James, I have a 4.3 GL volvo penta that emits a popping

Customer Question

Hello James,
I have a 4.3 GL volvo penta that emits a popping sound at high rpm. Another way to reproduce misfiring at 4000 rpm is to turn on the exhaust blower or lights, which causes the engine to loose all RPM for 1 second, as if you fill the ignition and then turn it back on. The engine bucks violently.
Same if you hit the power trim switch when cruising on plane.
The engine is always serviced at a volvo penta dealer. They changed the plugs and wires this week, and told me there was 2 fouled plugs on the port side of the engine. They checked the alternator and coil, said both were fine. It also has a new cap and rotor.
Back on the water this weekend and the same problem occurs, although it runs better with new plugs.
The engine has 320 hours, and I purchased the boat new in 2003.
It has been acting up for a couple of seasons now. But at this point it is unbearable and everytime we take the kids out, there are problems.
I am sick and tired of mechanics telling me that they water test it and there is nothing wrong with the boat.
Can you help me?
Submitted: 2 years ago.
Category: Boat
Expert:  Tan replied 2 years ago.
Hello. My name is***** sounds like you have a fuel starvation issue. Can you run the engine on another fuel source separate from the boat side fuel system? Fuel starvation will cause the issue you are having the popping is a lean fuel condition caused by not enough fuel.
Customer: replied 2 years ago.
Hello Tan,The volvo penta dealer assures me that they change the fuel filter every season when it is serviced for winter storage. It has a new cap and rotor, new plugs, new wires (all installed last week). And they did a carb kit on it, but I dont think that means that they changed the jets.The volvo penta dealer told me that they found 2 fouled plugs on the port side of the engine.However, on plane, and at 4000 RPM, simply turning on the exhaust blower, or the running lights, or hitting the sterndrive trim switch will cause the engine to loose power rapidly, although only for a second. The engine behaves as if you killed the ignition for a second while running, and then turned it back on before the engine stalls.This is a 4.3GL volvo penta with a 2BBL carb.
Expert:  Tan replied 2 years ago.
Ok these are all the GL models which one is yours? This is typically a voltage supply issue. Check the main engine harness plug. This is the large round plug where the boat harness plugs to the engine harness. This plug can work loose and cause like you are having. This is a voltage issue. So check all the grounds and positive battery cable connections. 4.3GL-A, 4.3GL-B, 4.3GL-C, 4.3GL-D4.3GL-E, 4.3GL-EF4.3GL-G, 4.3GL-GF4.3GL-J, 4.3GL-JF4.3GL-P4.3GLMMDA, 4.3GLPMDA, 4.3GSPMDA4.3GLPBYC, 4.3GSPBYC, 4.3GIPBYCCE, 4.3GSJBYA, 4.3GIJBYA4.3GLPEFS, 4.3GiPEFS4.3GLPHUB, 4.3GSPHUB, 4.3GSPHUS, 4.3GIPHUSCE4.3GLPLKD, 4.3GLPLKE, 4.3GSPLKD, 4.3GSPLKE, 4.3GIPLKDCE, 4.3GIPLKECE, 4.3GSJLKD