Yamaha pro 50

[GregL]

I just bought a yamaha Pro 50. I have no knowledge of Yamaha engines. This one runs really rough on low speed Idle. Once it tachs up it runs perfect. But, occasionally the oil level light comes on and it runs even worse . If I let it idle for a couple minutes the light will go off and it runs good again. The oil tank is full.

 

[BaileysBoat]

Re: Yamaha pro 50

Nice motor. I have a 1986 model and it's been great.

The oil reservoir has a float operated sensor to activate the low oil alarm and and put the PCM into limp in mode. This limits engine rpm to 2500 or so.
Might want to check the float is free.

When running in limp in mode the idle should be smooth, so likely you have another issue, probably idle circuits one or all of the carbs, or synchronization

The Seloc manual will help you.