Tachometer reads too high - Volvo Penta I/O

[Glastron175]

My tach reads at about 2500 RPM when barely idling, and at WOT reads over 6000 RPM.
My engine is a 3.0L GS MEFS (Charcoal Volvo Penta). I believe either 1999 or 2000 year model. Any ideas what would cause this, or a fix?

 

[vfrkent]

Re: Tachometer reads too high - Volvo Penta I/O

On the back of the tach there is a switch for switching between 4, 6 and 8 cyl engines, take the switch and move it back and forth a couple of times then return to the 4cyl position, the contacts start to get a little corrosion on them and the tach misreads the spark count.

Regards,
Kent

 

[Glastron175]

Re: Tachometer reads too high - Volvo Penta I/O

Thanks much. I'll give that a try.