prop too small?

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jrohrbaugh
Posts: 70
Joined: Wed May 08, 2013 2:57 pm

prop too small?

Post by jrohrbaugh »

I have a 14 R 10 wheel on my 350 with the universal 35m engine.

Looking at the similar sized boats equipped with a Yanmar my prop appears to be really small

I am able to reach 3,000 ok and routinely cruise at 26 - 2,800 rpms to achieve 6.5 kts.

Does this seem to be similar to others who have this set up???

Jamie
S/V Soixante
sail 444
wolfe10
Posts: 587
Joined: Mon Dec 11, 2006 2:58 pm
Location: Ft Myers Florida

Re: prop too small?

Post by wolfe10 »

Jamie,

The way to tell if you have the proper pitch prop:

In smooth water, clean bottom with engine warmed up, go from low RPM reasonably quickly (just avoid cavitation which can give false signals) to WOT (Wide Open Throttle).

It you get to governed RPM very quickly, the prop is too small (diameter and/or pitch).

If you can build to within 200 RPM of governed RPM as you accelerate, you have the correct prop.

If you are more than 200 RPM from governed RPM, you have too large a prop (or very heavily loaded boat, or dirty prop or dirty hull, etc).

Brett
Brett Wolfe
C350 #180
"Vindaloo"
Ft Myers FL
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BillBerner
Posts: 110
Joined: Wed Oct 13, 2010 11:50 am
Location: Hastings on Hudson, NY
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Re: prop too small?

Post by BillBerner »

Based on my disappointing motoring experience with my C350, I'd say that if you are making 6.5 at cruising rpm's with no current behind you, TOUCH NOTHING!

Bill Berner
2003 C350 #66
Spartina
Long Island Sound
jrohrbaugh
Posts: 70
Joined: Wed May 08, 2013 2:57 pm

Re: prop too small?

Post by jrohrbaugh »

reading again the note from Gerry it looks like we have the right prop.
Maybe the new bottom paint will help overall performance.

I can tell you that the prop is small compared to those set up with Yanmar engines specifically on the 375 series.

Nothing left to do but upgrade to a larger boat!

Thanks Bill
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