50hp Merc. 3 cyl. bogs out at WOT

[autogun]

I recently bought this 16' Gruman Skidaddle w/50hp 3 cyl. Merc. I think about a 1989, after it sat in the elements (Buffalo, NY) for at least 8yrs....Well, I installed new impeller, spark plugs, fuel filter & priming bulb. It starts right up, idles and trolls fine...try to throttle up and, it does a little, maybe halfway, but won't plane off. I thought maybe it just needed to be run, I've had it out on the lake a couple times...It will go in spurts for maybe a couple minutes at most...and then slows down...I have ordered a carb kit, that's in the mail...any help would be greatly appreciated...Thanks

 

[wellsc1]

Re: 50hp Merc. 3 cyl. bogs out at WOT

Sounds like your on the right track. Since your attacking everything in the fuel system, include overhauling the fuel pump too. The diagrams are likely set up too. Also see if there's a fuel filter inside the cowling that's clogged.
wj
A motor that sat for too long seems to grow problems like mold does on a boat deck. One more thing, consider replacing the water pump impeller. While it may seem to pump properly, the rubber fins can be brittle, break up after running a while, clog up the engine water ports, and seize the engine. I'm talking from exerience on this one! $800 later, I had my 2-cycle, 40 hp Mercury outboard running again.

 

[Silvertip]

Re: 50hp Merc. 3 cyl. bogs out at WOT

There is a simple test that can determine if you have fuel pump issue which is my guess. When the engine begins to bog down, squeeze the primer bulb several times. This action simulates the work fo the fuel pump. If the engine picks up then the fuel pump is the likely problem. Since this is an engine that sat unused for a long period, you might also run SeaFoam fuel treatment in the fuel. It may not be an instant cure for partially clogged carbs but it may help. The problem is that the engine is currently running lean. Continuing to run it that way means the engine is not getting enough oil either and that can lead to seizure and severe engine damage.