Where is that RPM Tach output signal

[TheSwedishDude]

Hi Guys,

I am new to this forum and bought a 2000 vmax 1200 in may.

Have already done some modifications and I am currently adding a digital speedo with tach.

I am trying to locate the “Tach Output” or “RPM Signal Output” on the max for the Signal input for the new digital speedo with tach.

Have any of you added a tach and know where I can get the signal.

Tried the 3 wires behind the existing tach. No luck.
Tried the wires from the input side of the coils. No Luck.
Tried the front of the coil/spark side. Works but is not very easy to acess.

Any suggestions?
:ummm:

- TheSwedishDude

 

[thor_eyerdhal]

This is the grey wire behind tach...

 

[TheSwedishDude]

Ok. I will try again tomorrow and reply...

 

[one2dmax]

You will likely need to set your tach to single cylinder or even a "half" cylinder mode if that is available.

 

[maleko89]

Agreed with Sean. The Vmax is wasted spark ignition.

Sent from my SM-G920P using Tapatalk

 

[Bill Seward]

I believe any engine that has the ignition pickup driven at crank speed has a wasted spark. Unless, of course you are discussing a two stroke engine.

Too bad there isn't away to save all these millions of wasted sparks.. Like for the sad day your ignition takes a dump..

 

[adambweird]

If you use the grey wire thats attached to the back of the tach, odds are good youll need a signal filter to be wire in to get the new tach to read right. Koso has an adjustable one that works great! Just get the settings close on the new tach and turn the screw on on the filter til the needle smoothes out and the new tach matches the original when revved.

 

[TheSwedishDude]

Wow thanks for all the replys. Great to see such an active forum.

I tried the grey wire again today. Didnt work.
@one2dmax: The RPMs show correct when connected directly to the output side of coil going to the spark plug, and it is programmed for 2 cylinders.

Went on forum search and found this: http://cbrforum.com/forum/cbr-600f-15/chinese-ss182-digital-speedo-installation-tips-152756/page3/

Although it is not the same speedo it mentions a signal filter as adambwierd says. I might try KOSOs. Already bougth the digital speed adapter.

Some forums also mention trying to get the signal from the pulser aka pulse generator.
Where is the wires located. Do you know?

 

[one2dmax]

You're main signal feed to the CDI (pickup coil) is the pair of wires coming up from the left side stator cover. Look for the orange and black pair of wires. Connection behind the battery.

 

[TheSwedishDude]

Thanks Sean,

I have now tried the Orange wire and the gauge is set for 2 cylinders but then shows 6000 RPMs at idle which is 1000 RPMs on the original tach located above the faux tank, so even though I give a signal that the sppedo/tach can read it is way to high.

The correct signal and RPMs I got directly from the ignition side of the coil.

:hmmm:

Back to the drawing board...

 

[MaxMidnight]

Is it a Koso unit you are fitting?

 

[one2dmax]

As I said, some tachs require a 1/2 signal but the same guy that sells the Koso I think sells a signal cleaner for lack of a better word.

 

[MaxMidnight]

You mean one of these?

From experience with my RX2n it will work OK from the grey wire with OE coils (setting was 4C-2P LoAct)
but the filter was needed when I swapped to CoP's

 

[one2dmax]

That's it!