rb,
I counted them once using a mirror and marking one tooth and then slowly
rotating the engine by hand. I believe the number is 41 or 43 teeth. Some
magnetic pickup tachometers can be adjusted for a small number of teeth, but
the ones commonly available at places like West Marine have a smaller range of
adjustment and are more matched to the higher number of teeth on a flywheel.
Here's a alternative tachometer that works off the fuel injection pulses, and is
very accurate and also records engine operation time like a hobbs
meter.
manddsmallengine.com
In an over abundance of curiosity about the revolutions of my engine- I have
both.
Patrick
________________________________
From: groundhog groundhogyh@...
To:
AlbinVega@yahoogroups.com
Sent: Tue, March 1, 2011 12:02:38 PM
Subject: [AlbinVega] RPM gauge..
I got all excited one night and ordered a bunch of Faria gauges.
I blindly picked the diesel Tach that has magnetic pickup. I figured you just
glue on a magnet somewhere and away you go.....NOT.
The magnetic pickup the Tach is expecting is mounted next to a gear with many
teeth. When each tooth goes by, it sends a blip.
On my boat, I have what I believe is the MD6A. I looked on those pdf
maintainance files and noticed that the MD6B has a magnetic pickup. But the MD6B
isnt supposed to have it.
Well, on my boat, the magnetic pickup is present.
Does anyone know how many teeth are on that gear beneath the magnetic pickup?
Thanks.
rb