75 HP Evinrude Losing Power

[VMIJOE95]

I have a 1982 75 HP Evinrude. Once started I can start out at normal speed, then after about 30 seconds, it loses power. It goes from 4000 RPMs to about 2000RPMs. I have replaced the carbs (they have good compression), replaced all fuel lines, fuel filter, primer bulb. Does anyone have any ideas? I also have to spray carb cleaner to first get the boat started. After it runs a few minutes, I can turn it off, and it starts back with no problem. Any ideas on that also. Thanks in advance for your help.

Joe

 

[bowman316]

Re: 75 HP Evinrude Losing Power

my guess would be a bad power pack.
is that a 3 cylinder?

You are probally loosing spark to one or 2 cylinders. Try new ignition coils.

That is about the only thing you did not check yet.

 

[aesgator]

Re: 75 HP Evinrude Losing Power

Sometimes even a small hole in the fuel pump diaphram can cause a loss of power when it can't keep up with fuel demand. Its about $10 for a new gasket kit. Its simple, and if its not the cause its only $10, and you don't have to worry about that.

 

[VMIJOE95]

Re: 75 HP Evinrude Losing Power

It is a 3 cylinder.