Re: Nissan/Tohatsu propellers

DAVID_KAUTZ@HP-Sunnyvale-om5.om.hp.com
Tue, 19 Jan 1999 14:17:20 -0800


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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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You can calculate whether or not you have the correct propeller. See the
web page at: http://www.geocities.com/Yosemite/Forest/2727/calculate.html
to get the math and a good explanation. There are a number of other
interesting equations there as well (horsepower req'd to reach hull speed,
capsize ratio, etc....).

I've communicated with the Nissan tech representative via email a couple of
times about propellers. Their big concern is that a customer will over-rev an
engine by using a propeller with too small a pitch. I expect that the standard
prop. is a largish pitch to give the manufacturer plenty of protection.

The quick summary is that you want a small enough pitch so that you are in the
power band rpm (indicated in the engine specs.) at your cruising speed (hull
speed?) but not so small that the engine will over-rev at full throttle

Hope this helps,

Dave Kautz
P-15 #1632 "Tilly Lucy"
Palo Alto, CA

______________________________ Reply Separator _________________________________
Subject: Nissan/Tohatsu propellers
Author: Non-HP-ej (ej@tx3.com) at hp-boise,mimegw7
Date: 1/19/99 10:31 AM

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West Wight Potter Website at URL
http://www.lesbois.com/wwpotter/
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Hey i was on nissan marine's web site and see there are 3 different props
available for the 5HP. I haven't checked, but I'm 90% sure most of us have
the middle one. (7.2" pitch).

http://www.nissanmarine.com/techtalk/prop.html has the chart

I don't know much about props, but it seems to me from what I've read on
that site and others that our boats (which are relatively heavy for what 5hp
motors use typically used in) might benefit from a 7" prop. I know the
difference in speed between half and full throttle is minimal, so maybe a
smaller pitch would help us fight the waves when the going gets rough. Any
comments?

Anyone know a dealer that sells nissan/tohatsu props cheap? I could probably
use a spare anyways, so I should try the experiment.