Fuel Problem 1977 Evinrude

[MWENGER1]

Hi,

I have a 1977 Evinrude 9.9 HP. When I run this motor wide open or 3/4 throttle, it runs great but when I slow down to iddle it sounds like its running out of fuel, then I squeeze the primer ball and then it sounds normal for a few minutes then it will do it again. It starts very easy when it is cold also. This motor has very few hours on it, which just means it has sat for most of its life. Any suggestions on what it may be? Thanks in advance for your help.

Mike

 

[ottertail]

Re: Fuel Problem 1977 Evinrude

If squeezing the primer bulb makes the engine run good then I would suspect the fuel pump as the problem, the rubber diaphrams can get stiff over time and some will even stretch, either case will cause the pump to not pump the required fuel. A fue pump issue will often show up first at slowers speeds because the pump has fewer crankcase pulses to operte on. By squeezing the primer bulb you have in effect become the fuel pump

 

[MWENGER1]

Re: Fuel Problem 1977 Evinrude

Thanks ottertail, It was one of my suspicians and will start their with your advice. Thanks for your help.

Mike