Erratic Tach ?

HntnFsh · 08-28-2005, 07:04 PM

I have a 175 sj and the tach is kind of erratic.When I first take off and start to build rpm it will go up to 6000-6500 and kind of waver then settle back to where it belongs,after a few seconds.I know the rpms arent near that high,and its never done it before.
Anybody have any ideas on whats going on,and maybe a fix for the problem.
Thanks
HntnFsh

jimh · 08-28-2005, 09:17 PM

If you haven't already, check for a loose connection.

259 · 08-29-2005, 08:00 PM

Yeah...Connections or....I had a similar problem on my boat. The weld around a metal bracket that goes around my coil, had come appart. I re-welded it and fixed the problem. I have a NR w/350 efi.

Boat Doc' · 08-30-2005, 07:46 AM

Check for loose connections, battery, tach etc. Do you have any charging problems? The tach is driven by the voltage regulater, its possible the tach circuit of the regulater is going out. Note that the tach circuit can fail and still charge the battery. In summary check connections then look at either the tach or regulater causing the problem.