1978 70hp johnson 70EL78C

My 70hp johnson starts up ok on a cold start but when i turn it off for about 20 minutes or so i have a hard time getting it to start again. Does anyone have any thoughts on this matter?

Re: 1978 70hp johnson 70EL78C

I have a 1982 Evinrude 70hp and I have similar problems but I'll tell you what I do. First of all, don't prime the engine after that 20 minutes, rather just turn the key to crank the engine a couple times. And it won't start, that's ok. Then, after you crank it a couple of times push the key in to choke while starting the engine( like when starting it cold).

This usually starts it for me. .

Usually, the engine gets choked prematurely and ends up flooding the engine.

It has something to do with the fuel system, so a good idea would be to clean the fuel filter screen and the carbs.( a rag will do the job)

Re: 1978 70hp johnson 70EL78C

Im headed to the lake now to try it out please stand by.

Re: 1978 70hp johnson 70EL78C

I went to the lake this morning, and ol Betsy fired right up. However, I have a new set of issues. When i left the no wake zone, i tried to throttle up but my 70 hp johnson just bogged down. I could never achieve WOT. I also noticed that my primer bulb would never get hard. Please help me. What am i doing wrong?

Re: 1978 70hp johnson 70EL78C

I also had the same issue yesterday myself, but I have a trick I use to make it work. When the primer bulb gets low(or when the engine runs out of gas like it did to me yesterday), hold the primer bulb up vertical and squeeze. For some reason, the fuel likes to come up through the hose better when the bulb is upright. You shouldn't have to keep the hose upright after because it should keep a constant suction unless it gets some air into it like a leak in the hose. Make sure the hose clamps around the primer bulb and end connectors are real snug, and if they are crimped ones or plastic ones, then you should get the adjustable stainless steel hose clamps to use.

When you say you never could achieve WOT, do you mean never since you've had the engine or just this specific time you went out?

Re: 1978 70hp johnson 70EL78C

This motor of mine has a mind of its own. Ar times, i can achieve wot but only when it wants to. Should i focus on the carbs?