15hp Evinrude wont idle

Was given a 1986 model 15hp Evinrude 2 stroke from a friend, it was all in pieces so i reassembled it completely and rebuilt the fuel pump and carb but it wont idle no matter what ive tried it will still rev down and die from maybe 45% throttle down...it has good spark, strong fuel delivery, no float bowl issues, jets are clean..any ideas for me?

Re: 15hp Evinrude wont idle

Did you link the carb roller with the throttle cam? The carb roller should be at the mark on the throttle cam at the exact point it touches the throttle cam. This ensures your spark is firing at the right time through the various throttle ranges, including idle.

Also, did you set the slow speed carb adjustment properly? Are you sure that both cylinders are firing?

Re: 15hp Evinrude wont idle

Other than above mentioned, it depends on just how far apart it was when you got it. If the manifold was off or you did not use new manifold gaskets, you may have a air leak behind the carb. Or even a air leak at the fuel pump/block gasket juncture, or even carb gasket.

Re: 15hp Evinrude wont idle

The motor was disassembled to the point that the powerhead was out of the casing, when i reassembled it i used brand new everything all around, both cylinders are firing, i installed new plugs and the slow speed needle is adjusted from the manual specs to 1 1/2 turns out from lightly seated..i havnt checked the carb roller cam yet but i will check back later with what ive found since im not near the motor at the moment.

Re: 15hp Evinrude wont idle

Did you ever find a solution to this issue? I seem to be having the same problem with my 1983 Evinrude 15hp E15RCTA. I have checked spark, cleaned carb, replaced fuel pump, and adjusted low speed needle to spec and then tried to fine tune per link and sync instructions. The motor will run on all speed smoothly except for idle. If I twist the throttle from fast to slow I can see the timing plate pull back to the point where it no longer has any kind of contact with the roller cam on the carb linkage. Is this the problem with the idle on my motor or is it something else? Also is there is kind of marking on the timing plate where the plate should make its initial contact with the roller on the carb? My motor is in pieces right now so I can replace some parts on the bottom of the powerhead but as soon as I get her back together Ill try to take video of it with my phone and upload to youtube to show anyone who is confused about my question. Thanks.

Re: 15hp Evinrude wont idle

I did actually figure my issue out, i rebuilt my fuel pump and double checked my timing plate and it was ok, what it turned out to be was the actual ball linkage at the end of the twist throttle, i turned it in about 3-4 full turns and it brought my idle speed up from no idle at all.