115 Evinrude sputters/no power until warm than runs great

[willy007]

Good afternoon everyone. I have a 1980 115 Evinrude that starts up great but runs very poorly for about 10 minutes or so. Occasional sputter when idling but stays running. When applying full throttle it runs at low RPM's for a while (doesn't seem to be missing at all, just low power). After a couple of minutes it will start to jump/jolt to life in short spurts until finally it runs like there was never any issue! After it "wakes up" it'll run the rest of the day without any issues even if I shut it off completely for a couple of hours and run again later (primary use is for fishing).

I have rebuilt the carbs, fuel pump, and tried a new fuel tank and no luck. When it runs slow I have tried pumping the ball and choking it as well and neither have any affect (ball is very firm the entire time). I believe the problem may be electrical but I have no idea where to start looking. Any suggestions?

I will try to post a video of this happening, I'm sure that would be much more clear than my description. Thanks!

 

[emdsapmgr]

Sounds like the engine is not firing on all 4 cyls when it first starts. To be sure, you can test for spark one of two ways: the cyl drop test, or you can use an inductive timing light that will show the quality of spark on each plugwire. So far your testing has been fuel related-see what you get when you do some ignition troubleshooting.