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  1. #1

    Default Evinrude won't idle at shifting RPM

    I just purchased a 1980 Evinrude 25 HP with tiller steering and throttle. After lubing the cylinders and cleaning the carb the motor started effortlessly. There are a few minor issues to deal with, the first of which is the fact that the motor dies when I idle down to the shift RPM level. I have no idea how long the unit sat before I bought it. The motor sounds so strong with the throttle open, or even just a little bit open, but I obviously can't even test the gear box when I can't shift it. There is a strong stream of water being expelled by the impeller, and it was really smokey at first until the extra lube oil burned off. We've tried adjusting the lean/rich screw all through its travel, but with only minor difference. Is there any other way to adjust a 2 stroke carb? I had to jury rig the fuel supply by hooking directly into the fuel pump(I don't have a fitting). Could this be a part of the problem? What else could I check? Sorry to ask so many questions, but this is only my second outboard motor and my first 2 stroke. Thanks for your help!!

  2. #2

    Default Re: Evinrude won't idle at shifting RPM

    First of all sir, thank you for your help. I have recorded compression 110psi on both cylinders and the pressure held for quite some time before being released. Some of the Youtube videos on this subject present a wide range of readings as being "good" compression. What is good for my motor? The other thing you said I should test was the spark, and it jumped half an inch easy. What is the actaul plug gap for this motor? Would new plugs be a good call? When you talk about the "slow adjust" you mean the rich/lean screw right? There are no other adjustment points on this carb, are there, without doing something internal? How about a carb rebuild? Please remember that the motor started very easily. Anyway, thanks again, and I look forward to hearing your response and following your advice.

  3. #3

    Default Re: Evinrude won't idle at shifting RPM

    Wow, I am pretty confused by this, guys. I've tried adjusting everything, but my son noticed that the rubber retainer on on the air idle screw has the square tab broken off. The broken off tab is still in its slot, but could this be a way that it is sucking air? The retainer is available, but should I get a whole rebuild kit? Would there be any value in a fuel pump rebuild? Thanks again!

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