Mercruiser 4.3 sluggish???

[skimm1972]

Hello I just bought a 1990 crestliner with a 4.3 mercruiser it ran fine the 1st time out it got up to 38 mph....the 2nd time i was running out to the fishing spot in 3-4 ft waves running fine 3/4 throttle we hit a good wave and the motor sounded like it wanted to die and we lost speed...it sounded like it was starving for fuel then it took of again and ran fine??...we trolled for a few hours everything ran well, when we went to go in it throttled up nicely to about 1/2 throttle then got "doggy" again this time for a few minutes until it took off again, but this time I could only hit 32 mph?? I'm a novice boat owner and would be happy to hear any suggestions before I haul it in to a repair shop...I was thinking fuel filter?, hole in the gas line?....

THANKS
MIKE

 

[Fix'em]

Re: Mercruiser 4.3 sluggish???

If you hit a really good wave and came down hard, I'd look to the fuel bowls on the carb. Often times the floats can stick if sent bouncing violently, or you can stir up a lot of very old sludge/crap sitting in the bottom of the fuel bowls that can clog needles and valves. Also, check the fuel filter. Again, a hard hit can stir up a lot of crap in the bottom of an old fuel tank and send it up to the filter which can block the flow and starve the carb for fuel.

 

[Bondo]

Re: Mercruiser 4.3 sluggish???

...I was thinking fuel filter?,

Ayuh,.... That's where I'd Start,... Check it for Water....

 

[skimm1972]

Re: Mercruiser 4.3 sluggish???

Thanks for the replys...I'll check the fuel filter and carb.

Mike

 

[scipper77]

Re: Mercruiser 4.3 sluggish???

If you just bought the boat you should replace the fuel filters, check the timing, set the idle, and clean out the flame arrestor just for good measure. Also if you have an inline water fuel seperator that might cause issues as well. Even if those items aren't causing problems it's good to know that things are in proper running order. A compression test never hurt anything either, but I'd start with the filter and seperator.

 

[skimm1972]

Re: Mercruiser 4.3 sluggish???

It was the fuel filter...running great!
Thanks