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Main Area => General GS500 Discussion => Topic started by: oldarmy on May 12, 2011, 04:57:10 AM

Title: tachometer?
Post by: oldarmy on May 12, 2011, 04:57:10 AM
hey guys im new to this forum but i have been looking at it since i got my 05 gs500f in last october.  loving it but the other day i noticed that the tachometer is offset by 1800 rpm.  when i turn the key on the tach jumps straight to 1800 rpm and sets there.  then when i start the bike it "idles" at 3000 rpm.  it doesn't idle high or anything different than before other than the tachometer is 1800 rpm higher than it was before.  i already pulled the tank and tack to see if any wires were rubbed but everything looks perfect and i cant figure it out.  the bike runs fine its just bugging me to death.  any help would be appreciated.
Title: Re: tachometer?
Post by: ben2go on May 12, 2011, 05:22:48 AM
Sounds like your tach has lost it's calibration.Cheapest thing to do is replace it with a good used unit.Be careful because the older bikes have cable driven tachs and the newer bikes have electric tachs like yours.I am not exactly sure when this change occurred,maybe 02 or 04.
Title: Re: tachometer?
Post by: oldarmy on May 12, 2011, 07:03:17 AM
thanks for the info.  i was afraid that was gonna be the case.  i looked a little on fleabay and they range from 60 to 150.  so ill look around and see if i can find one on the cheap.  but its not hurting anything right now so ill get one when the price is right. 
Title: Re: tachometer?
Post by: ben2go on May 12, 2011, 07:07:29 AM
Opps I made the right post just in the wrong thread.Sorry for the confusion.
Title: Re: tachometer?
Post by: Paulcet on May 12, 2011, 08:54:31 AM
Is that just the cable? Sounds kinda low for a whole tach.
Title: Re: tachometer?
Post by: Worm on May 12, 2011, 08:57:44 AM
So when you replace the tach, what happens to your odometer? You get to start at 0 again?
Title: Re: tachometer?
Post by: skirecs on May 12, 2011, 09:04:03 AM
tachometer and odometer are not related, one is off the cam, the other is off the front wheel

you can't open up the bezel and just rotate the whole bit behind the gauge print?
Title: Re: tachometer?
Post by: tt_four on May 12, 2011, 09:06:31 AM
It's too bad bad everything is sealed shut. It sounds like the tach needle just needles pulled off and put on straight. Unfortunately there's not really a way to do that unless you can get the tach apart.
Title: Re: tachometer?
Post by: oldarmy on May 12, 2011, 10:24:52 AM
Quote from: ben2go on May 12, 2011, 07:07:29 AM
Suzuki P/N 493222-001

$18.62 at www.bike bandit.com and should be $6 shipping.Mine was.


this part fits the 89-02 that is cable driven.  the one i need would be from 03-to current that is electrical.  that one is 176-180 plus shipping from bikebandit.  thanks though
Title: Re: tachometer?
Post by: adidasguy on May 12, 2011, 12:06:09 PM
Your tach is electronic. If it jumps with the key on and the bike not running, either the tach is bad or the electronics control box of the bike.
The way to isolate it would be to find a friend with a similar bike that has electronic tach. Remove your tach and plug it into the other bike. If your tach is OK, then its your electronics. If the tach jumps to 1800 with the other bike on and not running, it is the tach.
Title: Re: tachometer?
Post by: tb0lt on May 12, 2011, 12:49:47 PM
Quote from: adidasguy on May 12, 2011, 12:06:09 PM
Your tach is electronic. If it jumps with the key on and the bike not running, either the tach is bad or the electronics control box of the bike.
The way to isolate it would be to find a friend with a similar bike that has electronic tach. Remove your tach and plug it into the other bike. If your tach is OK, then its your electronics. If the tach jumps to 1800 with the other bike on and not running, it is the tach.

The 3 wire GS tach uses 1 wire to read the ignition pulse and 2 wires for -ve and +ve and is an otherwise self contained unit. The closest thing to a control box in the picture would be the Ignition control unit.. in which case, this situation means the ignition firing enough to excite the needle to the 1800 RPM point with the engine OFF. The chances of that are near zero because of the way the ignition system works on this bike.

So... the issue is probably just a dislocated needle or messed up zero calibration.
Title: Re: tachometer?
Post by: oldarmy on May 12, 2011, 04:07:43 PM
thanks for the help guys.  im pretty sure its the tach itself and i dont know anyone that has a gs so it looks like it will just have to bug me for a little while until i can afford to get another one.
Title: Re: tachometer?
Post by: ben2go on May 12, 2011, 04:31:00 PM
Quote from: Paulcet on May 12, 2011, 08:54:31 AM
Is that just the cable? Sounds kinda low for a whole tach.
I corrected that post.Sorry all.