Do I need a new tach?

[sea wolf]

My tach reads 900 rpm's when the engine is shut down. Is there an adjustment or do I need to replace it?

 

[Dunaruna]

Re: Do I need a new tach?

Does it zero out when the ignition is turned on (not running, just 'on')?

 

[Don S]

Re: Do I need a new tach?

Many tachs don't drop to zero when shut off. As long as it works at all rpms when running, no reason to replace it.