Tach problem

[Anonymous]

The tach on my bike (1980 GS750L) doesn't work properly. I have to hold the throttle at an rpm before the tach will lazily make it up there. Anyone know how to fix a sloooowww! reponding tach? I tried a tach off another bike and it seems to function normally, however that one doesn't work with/fit in my cluster.
Any Ideas?


Thanks,
Jamie

[Anonymous]

I think they are like auto tachs when they start working slowly then they are going out ( i.e. like your stator when its gone its gone) start checking Ebay and some salvage yards.

[Anonymous]

My tach has the same problem.

I've read here that one way to fix it, if you're handy and have a dremel, is to cut open the tach to clean it out and get it working normally (apparently the GS's tachs are magnetic). I've read of folks cutting the main ring around the face and removing the ring, allowing the tach innards to come out from the front.

I'm considering cutting a ring all the way around the white plastic about 3/4 inch from the face, and gaining access that way. Then, when epoxied back together, and re-assembled with the outer black sleeve, you won't know I ever cut it open.

[Anonymous]

Ok, I fixed my Tach this evening.

As mentioned, I cut a circular cut all the way around the circumference of the white PVC tach case with a dremel tool, then removed the two screws holding the internal frame of the tach to the remaining case half.

I then removed the tach innards, and proceded to clean them up and de-gunk them. The GS tach IS a magnetic type tach: the cable goes to a circular magnet that spins just inside (but not touching) a metal bell that is connected via a fine shaft to the needle. There is also a spring that returns the needle to the zero position.

Further disassembly was not required. In my case, the main problem was some hardened grease in between the bell and the housing that sits just outside the bell and halfway encases it. I cleaned this up, and also the bearings near the front where the needle attaches, with WD-40 then dried with compressed air. I HIGHLY recommend against using carb cleaner or brake cleaner, or any other harsh solvent, as it WILL immediately damage the flat paint on the face of the tach. If the face needs cleaning, use mild soap and water, then some compressed air to dry and remove any lint pieces before reassembling, as you don't want any lint sealed inside your tach.

To wrap it up, I chamfered the edges where I had cut, and epoxied the two halves back together with quick-set epoxy. Tomorrow, I'll sand down any high spots left by the epoxy so I can slip the black cover sleeve back over the tach and mount it back on the bike.

Good luck!

[Anonymous]

Cool! 8) I will have to get some cutoff wheels for my dremel.

Thanks again

Jamie

[Anonymous]

I got into my tach by prying up around the entire edge of the metal ring, then removing the the ring and the glass.

[Anonymous]

Wish I would have read that earlier
Well I am halfway there. I cut it apart and cleaned it now I just gotta get some epoxy to put it back together. It was definately gummed up was really gummy til about 3K or so. Now it's a lot better. Can't wait to get it back together to see how it works

[Anonymous]

The reason I chose the cut/epoxy method is that I figured:

1. It's easier. (IMHO)
2. I'll have a guranteed watertight seal when I re-assemble it.

[Anonymous]

Well got it back together and it works great.
Now I have another problem

[earlfor]

The excess epoxy dripped into your BVD's and its now been three days since you..................??

Earl :-) :-)

Well got it back together and it works great.
Now I have another problem

[Anonymous]

Ya got me

[DJones]

new tach problem

the housing on the engine where the tach cable attaches broke off. Now my tach doesn`t work. How do Ireplace this thing?

[Anonymous]

The tach cable screws into a rather substantial housing that is held in place by a metal tab and pulls directly out of the engine (with quite a bit of effort by the way). I don't see how this housing could have broken given it's substantial size. Are you sure the end of the tach cable isn't what's broken?

[DJones]

tach problem

yes, I am sure. The metal tab is broken off and the housing just rotates if u turn it by hand. The tach cable is also broken but, I have a replacement. How do I replace the housing? Can I just pull it out with a pair of vice grips? Doesn`t the end of the housing mesh with gears inside the engine?will I do any damage by yanking it out?

[Dink]

Re: tach problem

yes, I am sure. The metal tab is broken off and the housing just rotates if u turn it by hand. The tach cable is also broken but, I have a replacement. How do I replace the housing? Can I just pull it out with a pair of vice grips? Doesn`t the end of the housing mesh with gears inside the engine?will I do any damage by yanking it out?

No just pull it out , but be a liitle more careful when you go to replace it , like at least lube it in motor oil and fit the housing into place before you fit the cable.
Dink