Sticky Tachometer

[maboyer]

My new 1984 (8.6) S2's tachometer seems a bit 'sticky.' If I give it a little 'tap' with my finger it works.... It is the original control panel ( I think ). Any ideas?

This control panel has the 'id..t lights' plus the tach. I would like to install either a new tachometer or a complete panel of gauges.

All ideas appreciated.

Thank You,
Mike

(reposted from S2 forum)

[capttb]

On a gas engine the tach is driven by the coil, Most (?) boat diesels have a tach driven by alternator output (beats me how exactly) that can be a little touchy. Try cleaning the electrical connections for the tach., but if it works every time you tap it, you might be good. Lots of gauges are something to look at but other than temp. & tach. are usually the source of more worry than use on a diesel.

[Valiente]

It is possible that your alternator belt is slipping due to improper tensioning, or is on the verge of fraying and thereby failing. My Westerbeke tach is driven by the alternator (so to speak), and I didn't realize the belt had failed until I motored to and from the pump-out dock with a "twitchy" tach that eventually went to zero.

Luckily, I also noticed the coolant temp was over 200 F. After I let the thing cool off (no damage done except to my nerves), I changed the belt. The old one had turned into five or six rubber bands. Always carry a spare belt!