What propellers for SeaRay 270 Sundancer

[ancarol8]

I have a 1987 sea ray 270 Sundancer with 2 Mercruiser 165.
At present, on the boat are installed propellers 14.5 x19 L/R, which are not right: only 3600 rpm with WOT.
I would like to ask to the owners of the same boat :
1 - what propellers are working on your boat ? ( size, 3 or 4 blades);
2 - what performances do you have? (top and cruise speeds);
3 - what problems have you had for the optimum choice of the propellers taking into consideration also the difference of performances between clean and dirty hull ?
Sorry for my English, but I write from Italy.
Thanks in advance for your replays.
Antonio Alberto
Rome - Italy
ancarol8@alice.it

 

[techmitch]

here is a link to the prop chart but it only list 175HPs

http://www.searay.com/boat_graphics/sea_ray_prop_charts/1987.ENGINE,DRIVE%20AND%20PROP%20MATRIX.pdf

 

[Nehalennia]

Is the hull clean and the propellers in good condition?

 

[ancarol8]

Yes, the hull was clean and the propellers was new (Solas 3 blades), when I obtained 3600 rpm with WTO. Now , with dirty hull the engines do not exceed 3100 rpm.
Thank for your replay.
Antonio Alberto

 

[Nehalennia]

Well a 17" pitch prop may gain you a 200 RPM, but your WOT should be between 4100 and 4600 (if I recall correctly) on the 165's

Switching over to the 17" and getting to 3800 still isn't enough. I would think you may have some power issues because of the age. It sounds like time for a proper Marine mechanic to diagnose your engines.

Best of luck

 

[ancarol8]

Thank Todd,
also I think that the engines have lost power.
Antonio Alberto

 

[ancarol8]

Yes, probably the problem is the power loss of the engines, but I would like to receive messages from owners of boats the same as mine to know:
1 - what propellers are working on your boat ? ( size, 3 or 4 blades);
2 - what performances do you have? (top and cruise speeds);
Thanks
Antonio Alberto