On 2 Sep 2005 08:40:43 -0700, "boater435" wrote:

I belive my tach is not reading properly. I have an albin 27 family
cruiser with a lehman diesel the rpms seem to exceed the redline by
alot 500 to 800 rpm (guessing) the tach stops at 4100. I don't think
the engine would go this high. I am trying to find something to check
the rpms so I can calibrate the tach or repitch the prop. Any help
would be appreciated. Paul, Cape Cod, MA

Get a cheap non contact tach - perhaps one that reads a tape strip on
a shaft. Try it with an induction motor off load - they spin about
3590 or 1592 rpm.


Here's a note - an old note - that mentions this kind of device.

"On page 4 of the AIRCRAFT TOOL SUPPLY CO 1-800-248-0638
[great catalog]
there is a digital propeller tachometer, it is
hand held and works on 2-3 &4 bladed propellers. it has automatic shut
off, works to 45 deg. Pilots use it in the cockpit - its cost
$49.95!!!!!
aircraft tool supply
po box 307
1000 old US-23,
Oscoda, mi. 48750 "
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Brian Whatcott