Bavaria 41 engine size and propeller match for RPM

[boaterbob]

My Bavaria 41, 2004, with D 2 55 and saildrive 120 (2.2 gear ratio) runs great at 1800 rpm at 7 knts. D255 specs suggest max RPM to be around 3300. I can't get above 2400 and recently notice slipping at 2200 RPM at 8 knts (above hull speed). Do I need lower pitch prop to increase RPM? What is source of slippage, which is not a problem if I stay below 2200 RPM? clutch in transmission? Leave it alone? What is mfg. match for this boat? resource to match prop to boat?

[kavok]

Probably to much propeller pitch. You do not describe propeller model ad  its dimension.
My Bavaria Cruiser 40,  Volvo D 2 53 hp at 3000 rpm, perform 7,3 kts at 2000 rpm ; 7,5 kts at 2200 rpm.
FoF 18x13-3L propeller.

[symphony2]

Based on the information you have given you are indeed "overpropped". You don't say what size or type of prop you have. Without that it is difficult to suggest the easiest way of putting it right. Your engine is perhaps too big for the boat not necessarily a bad thing as Volvo have a big gap in power between the 40 and 53/5hp engines. So quite common to overprop a bit to get maximum revs of 3000 rather than the full 3300 as you don't need the extra power to achieve well over hull speed. To get the revs up near 3000 you need roughly a 2" reduction in pitch.

[Matay]

I hope this might help