Hello, List.
SInce joining the Tiger owner ranks I have come to greatly appreciate the help
and expertise from members of the list. I hope the following information
serves to return the favors in a small way.
Since I have an MSD breakerless distributor (but without the multiple
discharge electronics box), I recently had my original style tach rebuilt by
MoMa, who installed a modern VDO movement and electronics. Unfortunately, when
I installed it, it behaved quite erratically: it read at least double correct
RPM when major electrical accessories such as lights, blower or turn blinkers
were switched on. And above about 3000 RPM, it completely lost track and went
berserk. WIth no electrical accessories, it did read approximately correct at
idle speeds, but not consistently.
After discussion with helpful folks at MoMa and MSD, I was able to get it
resolved. MSD sent me several parts to try, free of charge. If these didn't
work, they recommended their tach converter, which costs about $60.
Fortunately, two simple components they sent did the job:
Connect in series between the coil negative and the tach trigger input lead:
1) a 10k ohm, 1/2 watt carbon resistor and
2) a 1N5818 Switching Diode. MSD recommended to try the cathode (striped end)
toward the coil, but to reverse it if this didn't work. Cathode toward the
coil worked
WIth these two parts, my tach works perfectly.
I hope this may be of help to others with MSD or other types of electronic
ignitions.
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