Evinrude 15 recedeing idle stop and no start

[thatone123]

I got this motor to run after some trouble. It really has me skunked. Cleaned the carb today with dip. Something told me it would still not run properly and that was the case. IT runs rough but runs then has what I am calling a receding idle where it slows down bit by bit then will not start until after about an hour. It can be reved up by hand to keep it from stalling until it stalls no matter what. Then IT does the same thing. I have real many times about how an electrical component like a CDI or coil will heat up then be hard to start, until it cools off. Anyone think this could be it? Spark seems to be good.

 

[thatone123]

Flooded may be the cause but the float looked proper, straight and true.

 

[kbait]

Model #?

 

[thatone123]

I got fooled again. I should have known better as I have worked on many of these 9.9/15...IT dawned on me that for one of these that is hard starting - you have to disconnect the natural safety switch. That is why you see many of them disconneted! You can't advance the throttle enough to start in hard starting conditions or cool weather. That is usually the first thing I do, but forgot. IT started right up, but still does the receding idle. Guess I will have to super clean the carb with a hydrosonic cleaner. Bowl had fine rust that I had to clean with steel wool. IT's maybe caked in some small passage, unless someone has another idea.

 

[thatone123]

I changed the clean carb with a clean one I had as a spare...Same problem so that rules out the carb for sure. Early on when I tested compression I thought it was off by an acceptable 5 points. Now I tested it again warm and it sure enough was 10 points off in compression. That is why it had the receding idle and rough at high speed. (I guess) So...as many have said here many times, you have to check that compression. Time to rebuild if I get the time! That would be a great post if someone posted what low compression in 1 cylinder tends to acts like.