i need help with my 1986 evinrude Model E10ELCDB outboard. It starts up fine and idles fine. It will even run good when i first start it up at high RPMs. the problem is that after it runs a little while (10 min) at idle and i increase the throttle, it will sputter and die out. This only happens at high throttle and after it warms up. I checked the fuel filter and its clean, changed the fuel lines. does anyone have an idea to what could be wrong. I have another posting concerning the carb. i soaked it in carb cleaner but was unsure about removing the cap on top of the carb before soaking. Other than that i have done this before on other motors so it is familiar. Thanks for the help.
It sounds like you have a component of the ignition system failing once warmed up. Have you tested spark once the engine is warm and failing?
That is not to say that you are also not having issues with the carb, likely the high speed jet. Did you ever get it properly and thoroughally cleaned?
Clean the carb first. Eg. A slight blockage in the fuel pipe would prevent enough fuel getting in a high rpm. Get a carb kit and replace all the bits - they are cheap. If it still does it it is probably ignition related. Check the coils for continuity and resistance - need a multimeter (cheap). Plugs act in strange ways if you drop them - replace them first. Stick it in a tank and rev it up and watch for sparks arcing from the lead (try it it dusk). Replace the capacitor and points - they are also cheap. Try everything until all you have left is the powerpack, then, if you beg steal or borrow a working one you can switch them to check if it works. Or, just buy one - I got one second hand for $50 but they can cost a bit more. I went through all the above on my current 15hp and it is now perfect, what with all those fiddly bits having been replaced - it was the powerpack but in the process it has gotten a good service and will run well for some time to come. While I was waiting I sanded it down and repainted it so I now have a very nice '86.
Sounds as though it could well be the carb. I think there is a good link in the FAQ part of this forum regarding carb. cleaning. I have had good success with spray cleaners and compressed air but others more knowledgeable than I strongly suggest a good soak in cleaner. I don't believe your motor has points and condenser ignition. When at WOT does it just run really bad or actually stop completely? Good luck. Rick.