1991 Evinrude 70hp problem

Hello, I have a 1991 evinrude 70 hp outboard motor that I’m having issues with. The motor starts great, idles great, but when ran at full throttle for a few minutes it begins to act as though it not getting enough fuel. It will run down then up, down then up 4 or so times before dying. It will start back up after choking it then the same thing again. I’m new to outboards ( my first boat) so any suggestions or help would be greatly appreciated. Thanks Justin

 

Sounds like a fuel delivery problem, you could try having someone keep squeezing the primer bulb as you motor along, if it keeps running with that, chances are that is the problem, and it could be you have a faulty fuel pump diaphragm, there is debris clogging the mesh fuel filter, or the fuel line is sucking in air somewhere, possibly at the snap-on connection.

 

Ok thank you sir. I will give that a try. If I find that the problem is in the fuel pump. Do they make a rebuild kit for it?

 

Yes, you can get a fuel pump gasket and diaphragm kit fairly cheaply. The pump has no moving parts, other than the diaphragm, that simply pulses with engine crankcase pressure cycles.

 

I had an identical issue. issue was the spark advance arm was sticking and it was opening the carbs before advancing the timing. Don't know if that is your problem but figured I'd pass along the info.