1987 Yamaha 50hp lack of power

[2000vikings]

I have a 1987 Yamaha Pro50LH motor that I am having issues with. Specifically, it starts and idles great, and runs at slow speed fine. As soon as I try to accelerate, the motor seems to cut out and only runs at 1/4 speed. I had the compression checked, and the three cylinders check out fine. Any thoughts or ideas on what is going on? Thanks.

 

[Ray Neudecker]

Re: 1987 Yamaha 50hp lack of power

All of the symptoms of a fuel restriction. Time to service the fuel system and carbs.

 

[Onset Flats]

Re: 1987 Yamaha 50hp lack of power

My yamaha 1996 50hp is doing the same thing. Runs great upto 25% power.

 

[Dunaruna]

Re: 1987 Yamaha 50hp lack of power

Possible fuel but also could be spark related.

3 cylinder 2 stroke motors are strange beasts, they can start and idle on one cylinder quite happily. I would check for spark on all 3 cylinders first and diagnose from that point onwards.