I just bought a 1994 Johnson 15. It starts easy and idles well, and the first time out it ran wide-open fairly well, but I did notice a few misses in it. It would run wide-open for a while, then start missing, if I backed off the throttle a little it would come out of it and run well again. It is getting worse, misses more all the time, even missing at half-throttle now.
I have replaced the plugs (and they both look good when taking them out). Checked compression - 110 on top, 105 below. Nothing on the screen on the intake of the fuel pump (and pumping the ball on the fuel hose while running didn't help). I did find some little tiny black chunks in the carb - think its carbon from the fuel pump cause it kinda smears like pencil lead when you touch it. Cleaned carb - didn't help. It does have a new powerpack that the previous owner put on.
I'm stumped....Any ideas??
Thanks for your help!
I have replaced the plugs (and they both look good when taking them out). Checked compression - 110 on top, 105 below. Nothing on the screen on the intake of the fuel pump (and pumping the ball on the fuel hose while running didn't help). I did find some little tiny black chunks in the carb - think its carbon from the fuel pump cause it kinda smears like pencil lead when you touch it. Cleaned carb - didn't help. It does have a new powerpack that the previous owner put on.
I'm stumped....Any ideas??
Thanks for your help!