Hello, I have a 1980 Mariner 50hp. After running until warm, light load, think of a 5 minute no wake zone. then going maybe half throttle for 30 minutes, i then do wide open for maybe a minute and I lose rpm's. During this 30 minute 1/2 throttle i can stab the throttle and get full rpm with no issues, it revs and runs great, it is only after an extended ful lthrottle run that i lose rpm. After it loses rpm i cannot get it back to WOT until the engine cools completely. it starts and idles just fine. i have gone through the carbs, new fuel lines from carbs to fuel tank. The tank is venting, i tried removing the gas cap while this was happening, no change. I tried pumping the bulb, little to no change, it seemed to flood out the engine more than help. It has a known good switch box and trigger in it. I resealed the lower unit, new water pump. It has 120 compression on all 4 cylinders. I did OHM the stator and i am high on the white/red and red leads. I have not Ohm'd the stator after it has been acting up. The fuel pump diaphragm's look new. I don't believe this is a fuel supply issue as it runs great until it gets good and warm running at WOT for a bit. I am thinking stator as it seems to lose its ability to switch to the high side after it gets hot. Just wanted some help before i spend the $250.00 for a stator. I also set the advance, used timing light like the book states. the carb butterflies are set correctly as are the idle screws. Spark plugs are new, fresh non oxy gas.
sorry for the rambling post, trying to provide as much info as possible
sorry for the rambling post, trying to provide as much info as possible
