[Mgs] Tachometers

Dodd, Kelvin doddk at mossmotors.com
Mon Sep 10 10:45:07 MDT 2007


Glenn:

Sometimes the amount of current passing through the white wire loop on
the back of the tachometer can be too high causing the tach to misread.
I've seen this happen sometimes when electronic ignition is added. The
problem happened a lot on the E-Type after adding a Crane ignition
module.

The suggested fix was to take the loop from around the plastic block and
pass the wire once past the pickup.

That worked on the Jags I dealt with, but I have not personally tried it
with the MGB.

It's worth a try though as the loop should have been cut and reversed
during the negative ground conversion so it should be easy to take
apart.

Kelvin Dodd


> -----Original Message-----
> From: mgs-bounces+doddk=mossmotors.com at autox.team.net [mailto:mgs-
> bounces+doddk=mossmotors.com at autox.team.net] On Behalf Of Glenn
Schnittke
> Sent: Sunday, September 09, 2007 11:01 PM
> To: mgs at autox.team.net
> Subject: [Mgs] Tachometers
>
> I've a couple of questions for the rocket surgeons.
>
> '67 B, converted to neg ground by DPO.
>
> The tach has always read about double what the actual revs are. Tried
a
> new
> voltage regulator and it fixed the problem with the other gauges, but
not
> the tach.
>
> 1. Realizing the DPO might not have done the conversion right, what
could
> be causing the tach to read double (or so) the actual revs.
>
> 2. I will be installing an MSD5 kit soon. I'd like to know what has to
be
> done to the tach. I put one in the Jag and the tach swings wild but
drives
> a lot better.
>
> Glenn
> Brute Force and Ignorance!
> 			- Kelvin Dodd
>
> Glenn Schnittke
> g.schnittke at comcast.net
> glenn.schnittke at vanderbilt.edu
> _______________________________________________
> doddk at mossmotors.com
>
> Edit your replies
>
> Mgs at autox.team.net
> http://autox.team.net/mailman/listinfo/mgs


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