Is It Easy to Replace a Tach?

[Wildcard]

Too funny - have to fix one of my tach's - not electric - a long steel wrapped cable with another small cable inside. Suspect the inner cable is fraying causing it to jump and therefore the tach is jumping all over the place.

I think it might be time to go electronic. Now to find a tach that will work with a 1965 reverse rotation engine - and a new tach that will fit in the hole in the dash.

Would rather have your problem! But vintage equipment is always fun .

Good advice on all fronts, particularly the part wher you look at the shrink tubes. Everything will last a lot longer if you take care of this!

Your inner drive cable is broken, this is why it jumps. The ends catch then break loose.
The pictured connectors are of the heat shrink type, it's clearly shown.
Id be wary of any advice that recomends the use of tape on a marine enviroment.

 

[Chuck Tribolet]

I think it might be time to go electronic. Now to find a tach that will work with a 1965 reverse rotation engine - and a new tach that will fit in the hole in the dash.

With an electronic tach, reverse rotation isn't relevant. Pulses is
pulses. And even with a mechanical tach, it isn't relevant, AFAIK, the reverse rotation
engines use a power head with normal rotation, and turn it around the other way in
the lower unit.

 

[DennisS]

Your inner drive cable is broken, this is why it jumps. The ends catch then break loose.
The pictured connectors are of the heat shrink type, it's clearly shown.
Id be wary of any advice that recomends the use of tape on a marine enviroment.

Any time I disconnect a wire I always tape it. It's just too easy for it to brush against another wire or contact block. Adhesive filled/shrink tubing connectors are the way to go for wiring.

 

[herman]

As a final step, I suggest a liberal coat of liquid electrical tape over the entire connector, lug, nut, bolt and all. The stuff is the best thing going for boat electrical connections.

 

[D_B]

Too funny - have to fix one of my tach's - not electric - a long steel wrapped cable with another small cable inside. Suspect the inner cable is fraying causing it to jump and therefore the tach is jumping all over the place.

I think it might be time to go electronic. Now to find a tach that will work with a 1965 reverse rotation engine - and a new tach that will fit in the hole in the dash.

Would rather have your problem! But vintage equipment is always fun .

Good advice on all fronts, particularly the part wher you look at the shrink tubes. Everything will last a lot longer if you take care of this!

It sounds to me that the flex cable is dry and is wearing the housing .. If it was broken it would more likely not work at all (this is common in older cars with cable driven speedos) this can be fixed by pulling out the flexible cable, cleaning it throughly , lubing it with a high quality silicone paste grease .. I've never seen good results from using wheel bearing grease, etc ... (I use Sil-Glyde paste from a tube, fantastic stuff, high temp grease, it's for lubing brake backing plates where shoes touch ... Sil-Glyde ) I've probably done hundreds and almost all can be made perfectly smooth again by doing this and seldom need to replace the housing & cable .. at the very least you will make a significant improvement.

Catherine ... does it move/work when tapping on the glass face? .. that would indicate that it's most likely the tach. OK, I see that Wildcard has you covered
I am a fan of the shrink/hot melt glue connectors too, they seal up relly well

 

[Darnold9999]

It sounds to me that the flex cable is dry and is wearing the housing .. If it was broken it would more likely not work at all (this is common in older cars with cable driven speedos) this can be fixed by pulling out the flexible cable, cleaning it throughly , lubing it with a high quality silicone paste grease .. I've never seen good results from using wheel bearing grease, etc

Good thought, I will pull the cable and have a look. I have repaired a few of these old tacs in my trucking days. Mostly I found that the inner cable gets frayed and starts to rub against the outer cable - causing it to jump. never had one quite this old however so it is possible that just some lube will fix it. Thanks

 

[Wildcard]

Define "jump"? does it work sometimes and not others? If so it's broken. If not, it's about to break.

 

[D_B]

The cable could be broken, but more often from what I've seen, what usually happens is that the cable lube dries up, cakes on the cable, and the cable starts wearing the inside of the housing, making it larger, the dry/binding cable is now free to wind up/whip inside the the housing, causing the needle to jump (although, it sometimes is the gage, the thrust bushing wears and now the rotating cage starts hitting the pointer drive)

 

[Wildcard]

Hey C, do you have a new one yet? If not order one and I'll fix it when i get back, MONDAY! Of course they want me to start work in Vequeis on monday too.... Gotta come home for a few days no matter what.

 

[Cacia]

I am trying to find a website where they have marine tachs...

can't believe you are heading back out