actual RPM's
 

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

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

There is a little gadget that has a rubber tip and records revolutions
sort of like a micrometer or caliper. A friend had one and helped
me calibrate a tach that was not reading properly after a pulley had
been changed. You hold it against the crank pulley for a minute and
it tells you the revs.

Somewhere I have another that I found at a flea market, but can't find
it now. I seem to remember the word "Starette" stamped on it - they
made a lot of small instruments.

I got a laser one for that purpose. Just put a little piece of reflective
tape on the flywheel and aim the laser at it. I think I paid about $40 for
it, maybe you can rent one.

"Jeff" wrote in message
news:1125697229.b7089977ad2a2f0c9398117204ee43cc@t eranews...
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

There is a little gadget that has a rubber tip and records revolutions
sort of like a micrometer or caliper. A friend had one and helped me
calibrate a tach that was not reading properly after a pulley had been
changed. You hold it against the crank pulley for a minute and it tells
you the revs.

Somewhere I have another that I found at a flea market, but can't find it
now. I seem to remember the word "Starette" stamped on it - they made a
lot of small instruments.

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 "
####################################

Brian Whatcott

On Sat, 03 Sep 2005 00:34:29 GMT, Brian Whatcott
wrote:

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.

Brian Whatcott

Make that, nearly 3600 rpm or nearly 1800 rpm.

Brian

"boater435" wrote in
ups.com:

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



Dump it. Put in a $65 TinyTach! Here's the diesel model:
http://www.tinytach.com/tinytach/diesel.php

Even keeps up with engine hours, automatically. Runs 24/7 for a whole year
on ONE 9V battery...(c;

--
Larry

"johnhh" wrote in
:

I got a laser one for that purpose. Just put a little piece of
reflective tape on the flywheel and aim the laser at it. I think I
paid about $40 for it, maybe you can rent one.



Takes 30 minutes to install a TinyTach....
http://www.tinytach.com/tinytach/diesel.php


--
Larry

You have mentioned Tiny Tach before , Larry. They seem pretty impressive,
and now the diesel model.
Are they very accurate?

"Larry" wrote in message
...
"boater435" wrote in
ups.com:

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



Dump it. Put in a $65 TinyTach! Here's the diesel model:
http://www.tinytach.com/tinytach/diesel.php

Even keeps up with engine hours, automatically. Runs 24/7 for a whole
year
on ONE 9V battery...(c;

--
Larry

"Garland Gray II" wrote in
news:NF7Se.106075$Ep.86997@lakeread02:

You have mentioned Tiny Tach before , Larry. They seem pretty
impressive, and now the diesel model.
Are they very accurate?



Digital....it's a pulse counter. It's as accurate as your quarts
wris****ch.

The first model was created for toy engines....jetskis, snow mobiles,
motorcycles, etc. I had one I transferred from jetski to jetski. It
didn't even connect to the engine! You wrapped its little antenna wire
around a spark plug wire and told it how many cylinders your engine had.
It picked up the pulses by capacitive coupling. Those had watch batteries
in them I don't ever remember replacing. The diesel models must have to
use a little more power, hence the 9V or DC power connection.

--
Larry

Larry, Thank you for the info on the tiny tach. I am going to order
one. Do you know if the transducer size (1/4" or 6mm) is found by
measuring fuel line? Paul

boater435 wrote:

Larry, Thank you for the info on the tiny tach. I am going to order
one. Do you know if the transducer size (1/4" or 6mm) is found by
measuring fuel line? Paul


I'm curious how it measures electronic pulses in a fuel line.

--
Stephen

-------

For any proposition there is always some sufficiently narrow
interpretation of its terms, such that it turns out true, and
some sufficiently wide interpretation such that it turns out
false...concept stretching will refute *any* statement, and will
leave no true statement whatsoever.
-- Imre Lakatos

"boater435" wrote in
oups.com:

Do you know if the transducer size (1/4" or 6mm) is found by
measuring fuel line? Paul



Nope, sorry. Ask them....

--
Larry

Stephen Trapani wrote:
boater435 wrote:

Larry, Thank you for the info on the tiny tach. I am going to order
one. Do you know if the transducer size (1/4" or 6mm) is found by
measuring fuel line? Paul


I'm curious how it measures electronic pulses in a fuel line.

I assume it is mounted between the injection pump and an injector, and
thus it could sense the pressure pulses, or are they sound waves?

On 4 Sep 2005 05:04:34 -0700, "boater435" wrote:

Larry, Thank you for the info on the tiny tach. I am going to order
one. Do you know if the transducer size (1/4" or 6mm) is found by
measuring fuel line? Paul

3 transducers to suit a 6mm or 7mm or 1/4 in (= 6.35mm) diam fuel
line. Measuring the line diameter is the way to go.

That's 0.236 in, 0.276 in and 0.250 in.

Brian W