Tacho Gremlins

[moondancer]

Hi folks. Any one got any ideas on this please - my tacho (runnijng from a 150 Johno) works sometimes, then sometimes acts like its retarded! Often, after a good run, then stopping for a while, when we start the motor again and throttle down, it reads very low , around 1000, when I know it's around 3.5 to 4000 - then if I jolt the tilt trim button it seems to slowly jerk its way back up to where it looks right! Wires all seem connected OK in the back - so any ideas welcome!

Lawry

[blaze]

Recheck and clean all electrical connections, double check the plug that comes outa the box
cheers
blaze

[banshee]

Don't know about the Jono but with a Merc the Taco is tied in with the alternator so if the alternator is playing up the Taco is to.

[moondancer]

Thanks for your replies - I'll have a look at both your suggestions. If it's the alternator, would I experience any other symptoms?

Lawry

[blaze]

Flat battery on a regular basis
cheers
blaze

[Reel-Job]

Hi Moondancer
I had the same trouble with my tacho on my mercury 150hp 97mod .My tacho stopped working one day and started again some days later then stopped for 1 year.What happened was the voltage regulator was playing up. And after I replaced the voltage regulator it worked fine.But check the connections as well because on the mercury the tacho wire is gray and when i zipped tied the harness togeather i pulled it to tight and unpluged the gray wire and the tacho stopped.Hope this is of some use to your GREMLIMS

[moondancer]

Again, thanks to all who have replied. I'll try all these suggestions tommorrow hopefully - next thing is I need a decent day to get the boat wet to see what happens!!

Cheers,

Lawry
ps excuse my dumb questions but where do I find the voltage regulator in a 150 jono please? (and what does it look like?)