Boat slows down

[w8krider]

Very strange feeling. Cruising at 30 to 35 mph the boat starts slowing down like the engine, or trans, are being held back. ( 2002 21 v Merc 350 mpi - 50 hrs ) all fluids are good, temperatures normal. If your try to throtle up when it begins to slow, the boat strains even harder. Please help, any sugestions?

[JASON739]

Does the engine RPM remain constant?

[ssrgeoff]

Do you have perfect pass?

[w8krider]

The rpm drops off like the motor is trying to slowly sieze. A loss of power, like i am pulling 10 riders all of a sudden. No, I do not have perfect pass.

[GIZMO]

Sounds like a fuel flow problem.

[hammlfam]

I only had my 04 21I for 2 days and had a very very similar problem. Believe it or not, my problem was a faulty fuel tank. At about 3000 RMPs, it would die down. It took the mechanics 2 days to figure it out. They tested EVERYTHING.

[JASON739]

Before anything, make them change the fuel pump. Do not let them install a pump booster. That was the original bulliten that was of no use. They must test the pump or install a new one first. How can a fuel tank be faulty? As long as it holds fuel and there is a hole for the fuel to run out into the supply the only thing left is the pump. My '02 problem was the original pump.

[hammlfam]

1. It wasn't holding pressure. It had a small leak.

2. When the factory cut the hoses for the fuel tank, they got ALOT of rubber shavings into the fuel tank. They then got all through my fuel lines, pumps, filters, etc.

[JASON739]

Lets be sure to cover that one in the assembly manual!

[w8krider]

Thanks, everyone for your ideas. It turns out to be water in the gas, pluged fuel filter and water seperator - replaced both filters and gas. The boat is running great.

[JASON739]

EXACTLY like I said!