28.5 Prop

[Scott]

Just pulled my boat for the winter. Hunter 28.5 with a Westerbeke 10hp diesel to push it. The prop on it now is a 12x9, this seems to be ok around the river but it really struggles in the tide. I think I am under proped for my boat. I can hit max RPM (3600) with a snap, the motor never seems to be working hard. The web site says it should be a 14x10 prop, but that is specified for a larger Yanmar engine. Any other 28.5 owners (or anybody for that matter) that can offer some advise?ThanksScott

 

[Eric Lorgus]

Need more horses

Scott:I have a 1987 28.5 with the Yanmar 18hp 2GM20F. I cannot hit 3600 rpm, more like 3200-3300 rpm under full throttle.You might be under-propped, but with only 10 hp, a more efficient prop won't make up for the horsepower deficit. I assume your boat has same displacement & weight as mine (7100 lbs). Max speed on my boat in calm conditions under full throttle is 6.6 kts, according to the knotmeter.Eric Lorguss/v Explorer

 

[Kevin]

Maybe more prop.

Dear Scott:Thanks for your letter. It sounds like to me, that you should be able to increase the propellers pitch or diameter. I would suggest that you remove the existing propeller and have a propeller shop increase its pitch to 10. This will increase the load produced by the propeller by apx. 12%. This addition of pitch should allow the obtainable boat speed to be increased at each given Rpm of the engine. You should also experience a greater ability of maintaining that speed when confronted with a heavy sea state. Hope this helps.Sincerely, Kevin L. Woody

 

[Scott]

Thanks

Thanks for your comments. I will take the prop to a shop and talk it over with them. I wonder if I am under powered, as I said, it never seems to me the engine is working hard, its just that my boat speed stinks in a current or in heavy weather. I seem to be the only 28.5 with a Westerbeke, but it came stock in the boat when new, I have the original paperwork. Again thanks for your inputScott

 

[Scott]

Beers

Eric,Maybe we could get together for a beer sometime, I'm in North East. I would like to compare notes on the 28.5 since there aren't to many around our area.Scottswells@dol.net