Tach acting up

[bkuhr]

Got 83VR non running, lot of work later runs great but tach reads low, and slow to respond to throttle changes. Dash was FULL of ants, disassembled, and flushed ants out with water, then dried with aircompressor. Any way to verify tach signal at rear of dash correct?

Volts?, Ohms? Think this signal is pulsing ground/vs 12v behind coil#2 @2xRPM?, May put o-scope on just to see what it reads. Haven't used my scope in long time-hope it still works.

 

Suspect tach gears/springs may have light corrosion needs lube (pull dash again:(), but would like to verify everything else first.

[dingy]

The tach is triggered directly of of the primary side of the #2 coil.

 

This same circuit, also triggers the fuel pump relay.

 

If bike is firing on #2, & fuel pump is working, it probably indicates this part of circuit is functioning.

 

Problem most likely lies in tach head.

 

Gary

[mbrood]

Typically if the TCI signal to #2 goes out or gets intermittent, the tach falls to "0" and then may pop back up when the signal is seen... the slow / sloppy response talks about needing the tach gears lubed.

[bkuhr]

Went ahead and pulled dash again, lubed tach gears and all OK now.

PS, used electrical contact cleaner/lube,non-conductive very light oil does not cause shorts on electrical circuits.

 

Have not got O-Scope out yet, may still go ahead any get readings just to see what is normal- if anyone interested?

 

Thanks for replies

Brian

[Venturous Randy]

Went ahead and pulled dash again, lubed tach gears and all OK now.

Thanks for replies

Brian

 

Hmmmm....I don't remember my tach having any gears to lube in it.

RandyA