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The tach on my Boss Hoss has started to act up. Every once in a while for the last year, maybe four times, when I started the bike the tach didn't move. I would be riding for a mile or two and then all of a sudden it would work again. After that it might not happen again for months and when it did the same scenario would repeat itself. I chalked it up to probably a loose wire and if it would just quit working and stay that way I'd remedy it. Yesterday I was riding it and the same thing happened and as usual it fixed itself after a mile or two. I met a friend for dinner and when I left the tach didn't work again. This time after about a mile it started working again but BACKWARDS. The needle swung starting from the 5000 rpm marker heading back to about the 3000 rpm marker rotating counterclockwise. It had never done that before but all of a sudden while I was on the freeway the needle goes back to zero and then starts working correctly again. I now think its my tach thats going bad and not a loose wire. Anybody got any ideas. Its an original 2003 Boss Hoss tach with a white face. If anybody has a good one thats the same and wants to sell it please contact me.

I'd first check all the connections on the tach and at the distributor .

This time after about a mile it started working again but BACKWARDS

were you in reverse at the time?????

Buck

hogv8 wrote:I'd first check all the connections on the tach and at the distributor .

I think thats a good place to start but a loose wire should result in an ON or OFF situation, not a cause to make the tach run backwards.

If a cursory check of the wires and grounds check out ok, I would try a new/test tach before digging deeper.

If it's shorting out who knows what it would do ?

grab any tach and temp install it to verify of its in the wiring or the tach. For testing purposes just grab any old tach off the shelf and extend the wires.

Probably the tach pooped the bed.
As far as I know, there is one wire, from the distributor and a ground. If the signal being sent to the gauge is faulty, I think the engine would run poorly or not at all. I suppose you could sent it to Autometer (I think they made them) and have it rebuilt
Maybe North Hollywood Speedo????

My tach and odometer acted up a few times. It's an '06 white faced Autometer. There were about three times when it did what your's did Dave. But interestingly enough, the milage on the Odometer was wrong. It was set to 'trip meter' at the time, and the 200 plus miles I put on went back to an older milage on the odometer. The Speedo stayed at 40 mph no matter what speed I traveled at. And about 10 miles down the road… it went back to normal. I wondered if it was some glitch that sent the speedo into 'calibration mode'…. and fixed itself with whatever it's designed to do if there is no definite input with button pushes, etc. It's been almost 2 years since that happened. So like yourself… still a baffling scenario!

I figured it out ... You tach has been Obama-ized. Most of the time It doesn't work and when it does, it does things ass backwards that benefits nobody. The best thing to do is rip it out of there, take it to a busy intersection and destroy it publicly.
This way the Replacement tack and all future tach's will know not to screw around with the BOSS ... just a theory