If your primer bulb on your fuel line looses pressure on idle first thing that I would check is for a worn seal in the fuel pump. If that's the case you can get a new fuel pump fairly easy for that motor.

 

That's the thing, it doesn't lose it at idle. It just dies with the bulb still hard. If I'm running out wide open, it will slowly lose it, like maybe have to give it a little squeeze once every 10 minutes of running.

 

With the resent temperature, humidity, and atmospheric pressure changes it is possible Your lean idle adjustment may need fine tuned. Also, she may just not troll well in the present conditions. You may have a partial blockage in the carburetor low speed jet that moves around causing intermittent problems too. There is a plastic knob on the left side of the motor which purpose is to allow repeatability to a set trolling speed. Turn it away from You a small amount at a time and see if there is a sweet spot. You are advancing the timing by doing so. If it helps the motor run better You Know the lean idle needs fine tuned. Good Luck .

 

Thanks for the advice. Today was the first time I had it out in the heat. It did fine earlier ing there year when it wasn't so hot. I'll try the adjustment and if that doesn't help, I'll see if I can find some blockage in the cab.

 

I,m leaning towards a fuel delivery problem, I hate adj things that have ran perfect for years, you could be sucking a little air at a lot of fittings, try fuel line,, blub,, connectors , pump,,before I,d dig deeper

 

Good advice from bountyhunter.

If problem persist after doing what bh suggested, you may then want to remove your low idle jet and spray some Gumout carb. cleaner down the port. Use the small straw provided to direct spray.
Before removing the jet, 1st run it all the way in carefully counting each turn it takes to bottom jet out. Then remove jet. When reinstalling after cleaning, run it all the way in and back it out exactly the number of turns it was.
Doing a lot of trolling sometimes builds up varnish in the low idle port.

 

X2 ,good advice start simple.

 

Noticed in the pics NGK plugs installed.....NOT discounting any of the above fixes, but all the OMC Johnson/Evinrude motors I've been around always ran best on properly gapped Champion plugs.
Your motor takes a UL81C at .030 gap.

 

sounds like the low speed jets are clogged up. if you try the other suggestions and they don't help try cleaning the jets.

my brother bought a 65 hp evenrude and took it to dale hollow. he started the motor and it idled great but when he gave it gas it would die. we put gas in the carb as he gave it throttle and it run great. I tore the carb down and the high speed jets was completely blocked. I had to take a piece of wire and push the red gunk out of the jets. went back out and it ran great. the jets can get blocked from letting the motor set with gas in the carbs.

 

I Have used SEA Foam in the gas and have sprayed in carb at high speed . Examples on youtube. Smokes like a freight train but cleaned it out , Good luck

 

I could be wrong, but, I believe that engine had points in it. Tune up maybe? Not to start an argument, but, I use NGK'S in my johnnie/rudest. Just seem to run better then champions. I know they say they run two hot and burn a hole in the piston. Knock on wood, not happen to me yet.