50 hp 2000 Merc, tuned up in Spring, new plugs,new fuel lines,priming bulb,in-line fuel filter,water/fuel separator fuel filter, new fuel along with Marine Sta-Bil,oil filter, oil, lower unit drained and filled with new lube. Engine ran like it was new for weeks. I was out today running at 4k rpms for about 15 minutes then all by itself the motor rpms slowed down to 3500, sounded like it was running on 3 plugs (has 4), it ran like this for about 10 minutes then on its own it ran perfect for another 20 minutes and then it slowed down again and ran like crap. I made it back to my slip running like crap. It does not stall out, starts right up, not over heating, plenty of oil.
Anyone experience this? Any ideas? The guy next to me at the marina says to replace fuel pump or it could be a bad coil. I don't want to just replace parts and still have the same problem
Anyone experience this? Any ideas? The guy next to me at the marina says to replace fuel pump or it could be a bad coil. I don't want to just replace parts and still have the same problem