Autometer Tach question

[Thevmaxrider]

I installed an Autometer motorcycle tach tonight and noticed that it is reading almost exactly 50% of the proper rpms. Anyone encounter this before and how do you correct it? Thanks for the help in advance!

 

[RazoR333]

There was a really good thread in here by lankee on the Autometer Tach hook up.
Did you hear any thing from Tom at COO on my R1 forks Jim?

 

[maleko89]

Jim, I'm assuming you are in 4 cylinder mode and only tapped into one coil. The problem is the Autometer unit expects two coil pulses. So, you need to tap into either both front OR both rear coils. Put a diode "facing" away from each coil to prevent feedback from one coil to the other.

[COIL]----->|--------+----------[TACH]
|
|
[COIL]----->|--------+

 

[Thevmaxrider]

Got it figured out with some help from a banned forum member. The Autometer Procycle tach can operate in either single or double pulse mode. For the Vmax you need to clip the brown wire loop and tape off the wire ends. This puts the tach in single pulse mode and it now works fine.

 

[[email protected]]

Jim,

Are you saying the tach has a brown wire that you can cut which puts it in single fire mode?

Curious about being able to use this tach in a different setup and if it can be used in single fire mode, it just may work.

 

[Thevmaxrider]

Jim,

Are you saying the tach has a brown wire that you can cut which puts it in single fire mode?

Curious about being able to use this tach in a different setup and if it can be used in single fire mode, it just may work.

Yep, you have to cut the brown wire to use it in single pulse mode which is required with the Vmax ignition system.