Loss of Top End RPM

[McFish]

Me and my mates are all experiencing a loss of top end RPM.
My 140 is only reaching 5200rpm, no missing or surging. 600hours
My mates 115 getting 4500rpm, 500 hours

Any ideas, is anyone else finding this?

[boats.net]

Start with checking compression, then fuel pressure (if fuel injected). Propeller selection can also cause insufficient rpm.

[kmoose]

Do you and your mate fuel up at the same location? Bad fuel, clogged filters, spark plugs....... All things I would check first.