Hello, I have a 2002 Mercury 115 4stroke EFI on a boat that I have had since it was new. Took it out today and it would rev to about 4800 rpm (normally around 5800) and then as the boat planed out it would drop to 4100 rpm with the throttle still full forward. It idles smooth but there is a little, very little but noticeable, missing at max throttle. I checked the fuel filter, it looked clean. I cleaned the filter housing. I checked the two year old spark plugs (have about 30 hours on them) and they were clean and properly gaped. I siphoned off the stabilized fuel from last fall, although it looked great and smelled fine, and put new gas with stabilizer and fuel injector cleaner in the tank. I checked the throttle linkage, no problems noted. I put the boat back in the lake and still have the problem. Could it be a cracked spark plug I can't see, all the plugs looked the same. What do I try next??
