Tach is WAY off

[Tharding]

Greetings!

I'm new here so thank you all for your patience!

I have a 1997 Glastron SE 195 w/Penta 4.3 GL and SX Outdrive. My tach reads many thousands of RPM's higher than actual as measured by a photo tachometer. Engine RPM's from idle to WOT are nominal based on the photo tach measurements. The tach on the cluster however is wildly inaccurate. PO seems to have done some work under the cluster as there is one black and one purple wire disconnected and wire tied. I have no idea if this is related. Any suggestions for how I can troubleshoot? Thank you!

 

[BRICH1260]

Make sure the setting on the back of the tach is set for six cylinders.

 

[Tharding]

Thank you! I'll check the setting as soon as I can!

 

[FunInDuhSun]

it could also indicate a poor ground to the tach.

 

[Tharding]

Make sure the setting on the back of the tach is set for six cylinders.

So it was set for 6 cyl. I'll try the ground issue next! Thanks again!

 

[Tharding]

it could also indicate a poor ground to the tach.

 

[Tharding]

Thank you! I'll look into this!