On Jun 2, 11:15 am, John H. wrote:
On Sat, 02 Jun 2007 06:47:13 -0700, JamesE wrote:
On Jun 2, 8:37 am, "jamesgangnc" wrote:
You're working in the blind without a tach."JamesE" wrote in message

roups.com...

Hello, I have a 1993 16 foot Excel boat with a 1993 85 hp yamaha
outboard, and am looking to buy a propeller for it. Right now the
boat has a 13.25" x 17" propeller on it and I don't have a tach but
would guess the wot to be about 4500 to 4800 rpm, and the maximum rpm
for this boat is 5500. I was considering switching to a four blade
13" x 15" propeller. The propeller I am looking at is from ql marine
by Volvo Penta. Does anyone know anything about this brand, I've
heard of Volvo Penta but never of QL. Also the boat typically is
pretty loaded, usually near carrying capacity, a total weight of about
2500 pounds including the boat and engine. I want to switch props to
make make towing easier but I also don't want it to over rev or
sacrafice tons of top speed. The propeller I am looking at has the
replacable hub and is made of aluminum, I am not interested in
stainless steel because it is too expensive. So I would apreciate
your opinions on wheter or not this is a good propeller for this
boat. Thanks for your help. James- Hide quoted text -

- Show quoted text -

Do you know of anywhere that I could buy or maybe rent a tachometer
that I could just use temporarily? I know that I can install a tach
but that costs about $100 and I was looking for a cheaper solution
because I won't need it all the time, just to find out the wot rpm.
Also if it helps the engine is a 3 cylinder two stroke outboard.
Thanks.

How about something like this:

http://tinyurl.com/2ccvkl

Cheap, will last forever, and can be used on your auto also.- Hide quoted text -

- Show quoted text -

How does that tach hook up? It looked like it determined the rpm
based on the voltage of the charging system, so would that work on an
outboard that doesn't have an alternator? I was also looking at the
tiny tach. Would that work on a three cylinder? I also saw a cheap
used yamaha tach on ebay so I'm going to keep an eye on that. Or I
have heard that there is also tachs that work by pointing it at a
rotating object. Are these accurate enough and could I just take the
engine cover off and point it at the flywheel while someone else
drives the boat at wot. Where would I get one of these type of tachs?