Gas engine tachometers

[MyPleasure]

Hi Fellas, has anyone else got this problem with the tachometers? The port engine tachometer doesn’t work at the bridge, but works fine at the lower control station. I haven’t checked the input wiring to see if the tachometer gets its power from the distributor, or from the alternator. I was thinking about just taking the tachometer from the lower station and swapping it with the tachometer from the bridge station.
I guess that the first thing to do is to check the wiring of the lower station tachometer and compare it to the bridge tachometer.
Anyway, if anyone has had this problem, any information would be much appreciated!

[Viper]

You could try swapping the port with the starboard tach and see if the problem follows the tach.

[bud37]

First, have a look at the back of the tach and look for a small screw that chooses 4/6/8 cylinder.....if there is one, operate the screw back and forth gently a few times and see what happens.....sometimes there gets to be some corrosion and messes with the tach operation. Worth a try ....good luck.

[MyPleasure]

Both good advise, I’ll definitely give them both a try this weekend! Does anyone happen to know where the tachometer gets their feeds from, the distributor or the alternator? The boat did not come with the wiring diagrams, so could anyone tell me what colour wire powers the tachometer?
Thanks again fellas, you guys are always great for information!

[MyPleasure]

Hi guys,
Well, I switched the tachs on the bridge, and the good tach worked on both engines, but the bad tach didn’t work on either engine. I’ll try playing with the 4-6-8 switch and see if that fixes the problem. If that doesn’t fix the problem, then I’ll pull one of the tachs from the lower steering station since we never run the boat from there. Last resort will be buying a new tachometer, if I can find one that looks the same as the original tach.

[Viper]

Turn that switch back and forth several times to clean the internal contacts. That helps sometimes. Depending on the tach, you may have to depress that switch before turning it.

[MyPleasure]

Thanks Viper,
I did try playing with the 4-6-8 switch, but no luck. I swapped out one of the tachs from the lower steering station and installed it on the bridge, and it works great! I never use the lower steering position anyway, so it works out OK! I might take the bad tach out again and play with the 4-6-8 switch a little more, but in the meantime, it’s sure nice to have both tachs working again. The port bridge tach hasn’t worked since we bought the boat.
Can anyone explain to me how to upload pictures on this sight? I’ve tried a few times, but still no success!

[km1125]

Try this:

CYO_posting_pics.jpg