Tachometer on Crack

[C17LoadSmasher]

Hey all,<br /><br />Long time since I last posted.. was in Germany w/ USAF. Anyways to my question: The tachometer on my boat indicates higher RPM than the engine is obviously putting out, IE, half throttle will read 6K, when 4800 is redline, but the engine doesn't sound like it is anywhere near redline at all. Any ideas? It has done this just a few times... TIA!

 

[Scottj25]

Re: Tachometer on Crack

The first thing I would check would be the setting on the back of the Tach. make sure it's pointing to the correct cyl. setting.<br /><br />If that's not the case my guess is that the tach. has gone bad, it may have a few burned out resistors.

 

[dmessy]

Re: Tachometer on Crack

My tach went bad in the same way. I read a post on this board that said my cell phone may have caused this. In fact, if I recall correctly, it started acting up shortly after my fishing buddy parked his phone direcetly over it. Did you have the same experience? Just wondering...

 

[skeffer]

Re: Tachometer on Crack

Just a short tech note I am a computer tech and we have always told people to keep cordless and cell phones away from the computers. Both of theese create a magnetic field when they ring and can wipe out thoose little 1.44 disk and if they are laying around sensitive equipment that field can do the same. put one near a compass and see what happen you can change the direction 180 degrees.