Hi, I have a 1983 MerCruiser GM 305 marine engine. The engine wont run right and boat wont even plane out. It was running not great but would plane out and get up to 3100 RPM, then I checked timing with a timing light and it was way off thinking, "oh I fix it it must be the problem" well I made it worse and cant get it back to were it was running at 3100 RPM. So now I got a boat that will get up to 1500 RPM. Here is all I did, I rebuilt Carb, new points, new condenser, new plugs, new wires, new filters(gas,oil,water separator), belts, did compression check(155psi is all) and new distributor cap. On my manifold is says it should run at 4400-4600 RPM and I have only seen it run like that when I first bought it 2 years ago and that only lasted a month or so. I don't want to have to rebuild engine as I just rebuilt one for my race boat. Also the boat misses. I don't think it is the cam, or timing chain as it was running OK while running at the top 3100 I got out of it a few days ago. I want it back to the 4500 RPM it is suppose to be. I need this running soon as this is my charter boat.
Thank you
I checked the mechanical advance at the distributor
Thank you
I checked the mechanical advance at the distributor