Lazy tach.

[fredintoon]

The tach. on my XS11SG has just started running slow.
It used to run fine (or at least, believably) but now reads zero rpm at idle and reaches 2,500 rpm at highway speed.
OK, I checked tech tips and it don't waver about, it gives a consistent low reading. Also the headlight brightens as the engine revs so that Q&D test shows it's charging. Besides the warning that a dead tach is a symptom of a dead charging system the tech tips have two posts, one says "Squirted with solvent, now works fine" while t'other says "Squirted with solvent, now don't work at all, will try contact cleaner later"
What I plan to do is start with the contact cleaner unless someone has a better idea?
Fred Hill. S'toon.

[Czekus21]

Lazy tach

I had a problem with my tach being lazy when I first got her, Took the tach housing apart and found one wire not making full contact. resoldered it on, put it back together and has been working fine ever since. Not sure if this will work for you. I tried everything else first before taking it apart.

[fredintoon]

Take the front off?

Thanks for the thought, I had made the assumption that it was a mechanical failure rather than an electrical one but the sudden onset of the problem gives me the sick feeling that you are right. To be sure that I understand you, you mean, you removed the front bezel & glass to access the instrument's innards? Damn, I hate doing that. One thing about a Smith's Chronometric, at least the bezel threaded off!
Fred Hill, S'toon.

[Czekus21]

Before takeing the tach apart, I would check the wires that lead down from it to where they connect to, and make sure that your getting a good connection, and the wires are good. Assuming that this is an electronic tach like my 79sf. Also check the sending unit to make sure it's good. The last resort ( givin ya might have to replace it) is to take it apart. I took mine apart thinking I was gonna have to replace it and wanted to see what made it tick.

[fredintoon]

new clues

Today my tach intermittently started working properly, jumping from the 2500 rpm lie to the 5,000 rpm probable truth, then dropping back again. This says "intermittent connection" to me, any guesses about where to start looking?
Fred Hill, S'toon.

[Czekus21]

If you follow the wire harness down from the tach, you will find a connector. If you do not have a fairing, it will be in the headlamp bucket, if you do have a fairing, it will be in the vinal harness bag cover that is tied around the harness. If you have a fairing, you'll need to remove it or take out the mounting bolts from the mount bracket, put a pillow or something on the fuel tank, and lay the fairing out of the way. When you gain access to all these wires, it's a good idea to clean ALL of the connectors and treat them all to some dilectric gease. This area would be the first place I would be looking at. Take your time, if you have any doubts about what goes where. Get some little address labels and label each wire, ( ie: 1-1, 2-2, 3-3, etc...) let us know if this solved your tach problem. If it didn't, there are other things that we can get into.

[fredintoon]

Czekus21, you nailed it!

The latest development in my tach story is that the tach stopped working altogether, not even the little light inside would light up.
Well I finally found the time to pull the headlight and check the tach connections inside (There's two of them). Pulled the white 3-pin connector apart, slathered it with dielectric grease and snapped it together and apart a few times and the tach light worked again.
Feeling that I was on a roll here, I did the same with the black 4-pin connector and now the tach is working too.
So simple to follow good advice, thankyou.
Whole job took 20 minutes and most of that was finding the correct size Philips screwdriver to take the headlight out.
Fred Hill, S'toon.

[Czekus21]

Glad that you found the problem and were able to have a " simple fix ". While you have things apart, It's a good idea to check all you connections.