Tacho Is Playing Up Folks

[grant81rs]

I'd be worried about the failure to drop beck to zero... that amcks of a physical problem with the needle rather than an electrical problem. I think I'd pull the instrument out of the casing and see if the needle has sticky bearings or any obstruction.

Rob

Well, Rob your the man"
After getting a few prices today for 2nd hand tacho $90 - $125 I went back over a few of these posts to see what I have missed, so I took your advice and pulled it apart again cause after the ride yesterday it did not return to zero, it was stuck at 2000rpm.
With it apart and in my hand, yes it was a little sticky, but it looked so fiddely to pull further apart and I didn't really want to take it any further so I turned on the compressor and reach for the "carbie cleaner" and took notice on the back of the can that said to keep away from "electric boards", WTF I thought, just a little won't hurt so I aimed it up nicely and gave it a little squirt and then hit it with some low pressure air.......BINGO it loosened up ASAP and now works a treat.....

I'll see what happens....

[grant81rs]

Gidday fellas,

Yep it is still is playing up............acting slow & not responding much from time to time

This time SteveD sent me up a new (2nd hand - that he tested on his bike) tacho last week, so I installed it, cleaned up the wire connection on the coil end and all is good to go with the tacho working fine again and the bike was already for a good 1600km Aussie apline high-plains ride over the weekend just pasted, the ride was great to BTW.

Tacho worked well for the first day at normal travelling speeds then on the 2nd day we came along this long straight road out near Walwa so we all opened up the throttles and I had my "ole girl" sitting on 100mph for a little bit and doing it very nicely indeed but when I backed it off to 60mph and looked down at the speedo & tacho, the tacho needle was still sitting on 6000prm and stayed there for about 15 minutes and when I pulled up at for fuel the needle was still at 3000rpm with the motor turned off, I could softly tap the tacho housing & the needle slowly fell back to zero....
The remainder off the weekend the tachno was now in slow motion and not responding as normal.......this was how my older tacho was so I gather the tacho mechanism itself is not the problem but I do not know what to do next!!

Any ideas fellas

[Roy Gavin]

Check the resistance in the coils, plug leads plug caps and plugs - something is cooking your tacho.

When I bought it my G/S tacho was the same , and then it died,
It was rough as guts too.
Finally traced the roughness to a NGK plug cap which was reading 22 k, and mismatched Jap twin lead coils the PO had fitted when he twin plugged it. A Boyer system with Boyer coils and new leads and caps sorted the roughness.

I have fitted a cheap auto tacho which works, but I dont really know what stuffed the old one, but it is worth a check.

[grant81rs]

Roy,

its sounds like a good place to start again, thanks once again...