External Tach..

[gareth]

Quick Question...

Where is the simplest place to hook up a test tachometer? In the Clymers I can see the tach shares a common white wire with the alternator and rectifier. Is it OK just to poke a probe in the connector...or is there a more convenient tapping point?.
Tank and seat off, btw. Ready to Sync...

Regards,

Gareth

[TopCatGr58]

Hey Gareth,

Most external tachs are designed to monitor and count the coil trigger pules. Our tachs are set up to count pulses from the alternator, so not sure but don't think they are calibrated the same.

You'll want to tap the negative trigger terminal of one of the ignition coils for you ext. tach. Our system uses the wasted spark system, so the coil fires on every revolution, one for power stroke of a cylinder, and then on the exhaust stroke of that same cylinder, while it's also providing the burst for the power part of the paired cylinder.

I would think your Ext tach would have a setting for how many cylinders, I would think you would need to set it for a 2 cylinder 1 coil system, so that it would count the pulse correctly! You should be able to also compare it with your bikes tach to tell what scale setting to use!
T.C.

[gareth]

Thanks, T.C,

That would explain the strange/off-scale readings on the older analog tach that I am using. Just 4/8 and 6-cylinder scales.

Regards,

Gareth.