Rich: There is something you can try yourself if you have an adventuous
spirit. Reference to an article by Frank Filangeri back in 2004 gave
instructions to replace a .2 uf capacitor ($2.00 at Radio Shack for a
two-pack back then) and then adjust the pot to calibrate the tach.
The capacitor, according to Frank's article, "...would be a tubular device
about 3/8" diameter X 5/8" long probably reddish or black in color.
Unsolder or clip out the old one and solder in the new. No polarity to
worry about, either direction will do. If this turns out to be the problem
and the tach appears to work, it must then be calibrated. There is an
adjusable pot on the back of the circuit board with a small screwdriver slot
facing the inside of the back of the tach case. I drill a 1/2" hole in the
tach case at that location so I can access the adjustment with the unit
fully asembled. Reconnect in the car then just compare it to a known good
tach/dwell meter and slowly adjust the pot to read the same at 1000, 2000,
and 3000 rpm. Tape over the hole when done to keep out dust and moisture.".
For a more detailed article on the electronic tach's operation and repair,
go to http://www.classictiger.com/techtips/motach.html . There you will
find an article titled, "Smiths Tachometer Calibration and Repair" written
by Mark Olson. (This was on a different Sunbeam Tiger web site when I was
referred to it by The List back in 2004). You will get technical,
disassembly, a schematic, troubleshooting, and calibration, information in
that article.
When my tach started reading incorrectly, I used these documents to replace
the capacitor and adjust the calibration pot. I am far from and
electical/mechanical expert but I am willing to give things a try. I was
successful that time. As they say, If I Can Do It, Anyone Can Do It.
(Even a Caveman? Oops! Cavemen don't like that!)
(The Other) Len
Vacaville, California, USA
1967 3000 MKIII, HBJ8L39031
----- Original Message -----
From: <RAntal243@aol.com>
To: <Healeys@autox.team.net>
Sent: Friday, July 06, 2007 7:04 AM
Subject: [Healeys] High rpm's
> Greeting Healeyphiles,
> While cruising last night at about 70mph in my BJ8, I noticed that
> the
> rpm's were consistently around 4400 while OD was engaged. This seems to
> me
> to be significantly higher than usual. What rpm should one expect at
> those
> speeds and if I am correct and the number is uncommonly high, what could
> be the
> cause?
> thanks much.
> rich antal
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