My friend has a 1994 5.0 MerCruiser with 2400 hours. I noticed earilier in the season while at cruising speed the rpms were dropping off, picking back up and consistantly repeating the process. I wasn't getting much respect from the others, especially on the way out if you know what I mean. By the end of the season, the symptom is definitely noticable to everyone and viewable on the tach. It would start out at 3300 on quickly dropoff to 2500 and back up. I can think of three problems of which two are valid. Problem #1 - bad gas (not likely, 20+ gallons added every week) #2 - carborator rebuild (probable) #3 - gas filter (highly likely. If you know my friend he's a "if it ain't broke, don't need fix'n") Any thoughts or ideas you guys might have would be greatly appreciated.