Hey guys I have a 1974 or 76. I can't remember at the moment. Mercury 4.5 hp motor. But it's SUPER clean. I've been running It for about three years now no problems at all. How ever the other day I was out and after moving around a bit stopping / starting. I shut it off for about 30 min. When I started it was almost sounded like it was missing. It ran for a min then shut off. Tryed it again same thing. Started it again and went wot. Soon as it got revved it ran like normal but as soon as I throttled down it started to Mis again. I cleaned the carb/ fuel pump. Checked the plug it's 3 yrs old but still looks great. Checked the grounds. I don't know if its the coil or how to even check it. Any ideas?? Thanks.
Sounds like a clogged fuel line. Something may have broke loose in the line and clogged it up. Was the vent of gas can open? Did you remove the carb and do a really good cleaning (cleaning out jets with a wire and so on. If the carb has a float it may be bad. If it was the coil you wouldn't be starting it. Sounds like a fuel problem somewhere.
Ok. Took the flywheel off to check the coil/magneto. And one coil was fine but the other had a wire broke right at the coil. Not a easy part to find. So I figured I'd try to solder it back in. We'll see how that worked later. But for now back scrounging the web for a replacement.