crazy tach...

[stumpy2000]

i have an '03 summit zx 800 that i picked up used & the tach bounces and gives random readings from time to time. occasionally it reads 1200-6500 rpm while idleing & some really wild rpm swings while rideing.the engine rpm sounds consistent (currently running factory clutching & pulls @ 7800rpm when it settles down) and i've confirmed that the idle rpm is consistent (set correctly & not raceing etc) with the use of a tach with an optical pick up (kinda hard to use while rideing lol).i would like to do some experimenting with the clutching on this machine but.... has anybody ever repaired this problem?
PS- all the wireing/plugs etc appear ok?

 

[Y2GREY]

Funny, Mine bounces then reads 0 when the sled is at idle. I flip the headlight switch to high and all is good. I don't recall if I had the issue before I switched out the controls. I was running the big encased plastic setup but now have just the minimal switches.

 

[MtnRidr4Life]

Sounds like a voltage regulator issue. I had the same problem till I put a new one in, and now works great. Sadly I went through about 3 headlight bulbs before getting it figured out.

 

[stumpy2000]

thanks i'll have to look into that,haven't blown any headlights yet but i was out for a rip yesterday & noticed my thumb warmer was on the fritz too might be something up on the bars causeing me issues