Help! My 18hp '72 Evinrude will not idle...

Hello all, this is my first post and first outboard so please be patient.

I recently bought an 1972 Evinrude 18hp and it starts fine but will not idle consistantly, it actually dies, especially if I don't ease off the throttle slowly.

I have rebuilt the carb and fuel pump, I have replaced one and inspected the other fuel lines (seem fine), I have spark (I used the inline type tester) on both plugs, new j6c plugs, and I am still not getting results. Another thing I am not confident about is the low speed nozzle adjustment, I am not sure what "seated" is. The nozzle will screw all the way down, is that seated?

Also, I pulled the new plugs today and they are black with oil, is that normal?

Thanks for any and all responses, it is appreciated!

Re: Help! My 18hp '72 Evinrude will not idle...

Quite possible that you didn't get the low speed jet clean, if you didn't remove it. There still could be some crud in there.

Lightly seated. Turn in until the needle is LIGHTLY seated-don't screw it in tight. Then back it out as many turns as the manual says.

Did the spark jump a 1/4 in gap with a hot blue snap? Could have a weak coil, but I'd bet carb.

Dissasemble and soak in carb cleaner over night. Blow out all air passages with compressed air. This is basically the same carb that is on my 25, and it is very touchy as to adjustment. Wait a few min after making a 1/8th turn adjustment. The engine takes that long to respond to a carb setting change.