1984 8hp model: E8RCRM

Hi everyone, I have a 1984 8 hp Evinrude that I use as a kicker motor for fishing. The problem is it starts up on the 3rd pull every time and runs great, push in the choke and still running great, after maybe 10 or 15 minutes it will start to spit and sputter and run real rough, sometimes it dies but always starts right back up.continue to have problems for up to 1/2 hour and then it coughs and will run great for the rest of the day. Trolling for salmon it is about 1/3 throttle pushing an 18' boat, does the same for kokanee which is a lot slower speed. I have tried adjusting the rich/lean mixture, but it keeps doing the same thing. Before I bought it the guy says it was used maybe 3 times and sat for many years, (it did have the original plugs in). I have been fighting this problem since I bought the motor about 8yrs. I sure would appreciate any help or suggestions. Thanks.

Re: 1984 8hp model: E8RCRM

88olympic said:

Hi everyone, I have a 1984 8 hp Evinrude that I use as a kicker motor for fishing. The problem is it starts up on the 3rd pull every time and runs great, push in the choke and still running great, after maybe 10 or 15 minutes it will start to spit and sputter and run real rough, sometimes it dies but always starts right back up.continue to have problems for up to 1/2 hour and then it coughs and will run great for the rest of the day. Trolling for salmon it is about 1/3 throttle pushing an 18' boat, does the same for kokanee which is a lot slower speed. I have tried adjusting the rich/lean mixture, but it keeps doing the same thing. Before I bought it the guy says it was used maybe 3 times and sat for many years, (it did have the original plugs in). I have been fighting this problem since I bought the motor about 8yrs. I sure would appreciate any help or suggestions. Thanks.

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Tried new plugs?
Current recommendation is Champion QL77JC4 or QL86C gapped at 0.030". Although I run NGK B7HS-10 in my '84 6hp .
It is important not to use resistor suppressed plugs.
Q in the Champion number = Inductive suppression. (L77JC4 or L86C are unsuppressed and would also be suitable)

Checked sparks?

Maybe carb requires cleaning ??? Not obvious from the symptoms though. Choking help at all? If it does it would suggest a carb clean probably necessary.

I think Id look at fuel supply too. Tried pumping the bulb to see if it helps? If it does then possibly fuel pump problem or air being drawn into the fuel line. Connector no.1 suspect.

My longshaft (Yachtwin) 6hp:

Re: 1984 8hp model: E8RCRM

You're describing the behavior on my '86 8 hp pretty well, and it drove me crazy for quite some time. I replaced the fuel pump, that made it better but didn't fix it completely. I noticed the cylinder driving the pump was oil fouling a little. So, I did a real thorough de-carb on it. So far, that seems to be the ticket. I think with that particular motor, you need very good compression to properly drive the pump.