2009 yamaha 40 hp for stroke issue

by Lucas harnack
(Timmins ON)

I have a 2009 Yamaha 40 horsepower Outboard 4-stroke. When I was using it 2 days ago I started it as usual got up on plane and it usually runs around 58 thousand RPM. After about a mile and a half it died down to 4000 RPM and continually got worse. I check the oil and it was over full and had a smell of gas. I drain the oil out to the full level check my fuel lines fuel filter and everything was okay. I tried the boat and it's still doing the same thing. I will change my oil but I'm wondering if there's something else that could be causing this?

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Jul 14, 2020
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starstarstarstarstar 		Found Problem
by: Jim

I think I found the problem. I replaced the fuel pump ($160.00)and tore the old one apart. Rubber parts looked good but the corrosion was unbelievable. I bought the motor used and I think the old owner used and stored the engine with ethanol gas in it. Check valves were froze and corrosion was so bad that the seals were letting gas get through the fuel pump and into the crank case.My advice is always use non-ethanol gas in your outboard motors. Pay now or you will be paying later.
Jul 09, 2020
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starstarstarstarstar 		Same problem
by: Jim

I have a 2004 Yamaha F90TLR(4 Stroke)with the same problem. Did you ever figure out what the problem was?

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