1990 15 HP Evinrude Wants to Stall Under Throttle

Hi all, new here and am hoping someone can help me out.

I have 1990 15 Horse Evinrude (model E15EESR) I thought I was doing myself well by getting rid of my old 6 gal tank and lines and getting a brand new tank and lines so as to NOT mix the old MTBE with new E-10 gas. Started fresh with a new tank full of E-10, measured the proper fuel/oil mix, also added some Startron as per instructions on the bottle.. Ran her a few weeks back on the DE River and ran great.

Then a few weeks later, took her out on the River again and had trouble.

Could only give her so much throttle, or the engine would want to bog down and stall. Going up river I could do 4.5 MPH max, or it would want to stall. Coming back down river could get to 8+ mph, or again would start to stall. DOESNT seem to be a problem with my inline fuel filter, primer ball etc. Have installed new plugs gapped to spec. Have checked the filter (mesh screen) in the fuel pump, seems fine.

Had knowledgeable friend do some testing. Tested all ignition stuff (except stator) and that was fine. He pulled my carb, cleaned it, did the rebuild kit, and then reinstalled it.

Still have the same problem. Engine is fine in neutral, at idle and as you give it throttle. In gear, you can only bring the throttle up to a certain point. Beyond that point you can see and hear it want to stall, if you back off the throttle at that point, it will continue to run just fine.

Any ideas?

Thanks much
BobEver@aol.com

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

Bob, I'm thinking your engine may be leaking exhaust and the carb is sucking it in when you give it throttle. Take the cover off and see if it runs better.

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

did your friend remove the highspeed jets and clean them. the ethanol will free up any little crap in the carbs, and those jets clog very easily. i've known people who have had to clean the carbs 3 to 4 times do to the fuel conversion.

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

Thanks for your replies.

Have run it with the cover off, makes no difference.

As to the carb, he cleaned it all out, blew it out, and installed the rebuild kit.

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

well it still sounds like the highspeed jets is clogged again. no need for a new kit. if he's careful. the jet requires a special tool to remove it. i made mine from a screwdriver. the second picture is courtesy, of, Frank, one of our great members.

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

I agree. If your engine is getting plenty of air and stalling then it's not getting enough gas to match the air intake. I cleaned my carbs so many times it's not funny. It wasn't until I used compressed air to blow them out that they work properly. Something flew out and hit my face during the last cleaning and I'm happy to say my 43 year old motor starts first time, every time and runs great.
I'm wondering if spraying mixed fuel into the carb during this stalling episode would tell anything. My theory is if you're not getting enough fuel delivery, spraying fuel in the carb may show an increase in performance. Then you'll know for sure if it revs up.

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

Thanks for everyone's replies, going to take it to a pro.

Re: 1990 15 HP Evinrude Wants to Stall Under Throttle

Took it to a pro (Barnacle Bills in South NJ). Fix was Barnacle Bill's installed new throttle cam and roller follower. When a friend was rebuilding my carb, he found a broken part in the engine compartment, evidently it was one of the above items. If I understand Barnacles correctly, because of the broken part, once the throttle reached a certain setting, it would cause the butterfly to close on the carb, thus causing the engine to bog down.