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Main Area => General GS500 Discussion => Topic started by: aaronmact on March 23, 2014, 12:07:49 AM

Title: Non digital tach to digital?
Post by: aaronmact on March 23, 2014, 12:07:49 AM
Hey guys my question is as above. My tach/ speedo cluster have seen better days. I saw some options for a full digital set up on chinabay. The speedo part is easy enough. Thats just a magnet with a sensor sadly. But how could I set up the tach? From what Im seeing theres no inlet for a cable like ours (unless im mistaken again). Its just wires. Is there a way to make it work or no?
Title: Re: Non digital tach to digital?
Post by: joweaver88 on March 23, 2014, 12:30:04 AM
Something like this might work

http://www.ebay.com/itm/DAKOTA-DIGITAL-DIESEL-UNIVERSAL-FLYWHEEL-TACHOMETER-INTERFACE-TACH-ADAPTER-DSL-2-/281290805253?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item417e3d1005
Title: Re: Non digital tach to digital?
Post by: dam on March 23, 2014, 07:44:49 AM
The digital tach should be able to get a signal from the ignition system to monitor engine RPM.
Title: Re: Non digital tach to digital?
Post by: radodrill on March 23, 2014, 09:00:21 AM
The newer GS no longer has a mechanical tach.

Most retrofit digital clusters will have a wire that you wrap around the spark plug wire to be able to read the RPM
Title: Re: Non digital tach to digital?
Post by: aaronmact on March 23, 2014, 12:09:53 PM
Sweetttt. So i just pull back some of the rubber around the spark plug wire and wire in the hot wire?
Title: Re: Non digital tach to digital?
Post by: radodrill on March 23, 2014, 12:11:34 PM
Quote from: aaronmact on March 23, 2014, 12:09:53 PM
Sweetttt. So i just pull back some of the rubber around the spark plug wire and wire in the hot wire?

No need to strip back any of the insulation; it gets the pulses by induction, so you just wrap the pickup wire around the spark plug wire.
Title: Re: Non digital tach to digital?
Post by: Badot on March 23, 2014, 12:55:43 PM
Quote from: radodrill on March 23, 2014, 12:11:34 PMNo need to strip back any of the insulation; it gets the pulses by induction, so you just wrap the pickup wire around the spark plug wire.

To add on... the spark plug wire has a high enough voltage running through it that you can detect when the plug fires just by having a sensor near it.
Title: Re: Non digital tach to digital?
Post by: robfriedenberger on March 23, 2014, 01:22:43 PM
Never ever strip back spare plug wires, your asking for trouble if you


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Title: Re: Non digital tach to digital?
Post by: Soloratov on March 23, 2014, 01:41:14 PM
^^ Like he said, that would be a major mistake if any type of wetness got in there ^^

Just splice into one of the coils under the tank. Most digital setups will come with the splice plug to allow very simple swap.
Title: Re: Non digital tach to digital?
Post by: adidasguy on March 23, 2014, 02:19:08 PM
You can use the signal line going into the coil. Not the orange wire, the other one. That is a 12v signal, one blip per rotation of the crank.
Title: Re: Non digital tach to digital?
Post by: aaronmact on March 23, 2014, 09:33:37 PM
Alright thanks guys. Hopefully Ill have on ordered and installed within a months time. Ill let you all know how it goes!
Title: Re: Non digital tach to digital?
Post by: Nocluejoe on April 17, 2014, 07:38:06 PM
I'm going to bump this thread I wired up a digital speedometer everything works good except the tachometer is off maybe a good 3k
I have a 2007
I used the red/black wire and hooked to my tach I believe it is not thick enough is there anything I can do or should I just hook a wire straight to spark plug and wire that to my tach?

Also orange is just a 12v wire for the tach?
Title: Re: Non digital tach to digital?
Post by: Paulcet on April 17, 2014, 08:59:50 PM
Quote from: Nocluejoe on April 17, 2014, 07:38:06 PM
I'm going to bump this thread I wired up a digital speedometer everything works good except the tachometer is off maybe a good 3k
I have a 2007
I used the red/black wire and hooked to my tach I believe it is not thick enough is there anything I can do or should I just hook a wire straight to spark plug and wire that to my tach?

Also orange is just a 12v wire for the tach?
Maybe the black/red wire pulses every other revolution (or twice per rev).  You say it is off by 3k... Do you mean it is always off by 3k, or do you mean that when the engine is turning at 6k, the tach reads 3k low.  Or high? And is the error greater when engine rpm is higher?

The wire is thick enough.  NO!  Don't hook a wire straight tot he spark plug.  Ok, go ahead.  Tell me how much smoke comes out.  Yes, the orange is just 12v power.  Try the black/yellow or white wire. 
Title: Re: Non digital tach to digital?
Post by: Nocluejoe on April 17, 2014, 09:41:42 PM
Okay will try that tomorrow I didn't mean connect the wire to the spark plug but wrap it around the cord like suggested else where on a few threads

If the black yellow doesn't work better maybe I can put both onto the tach?

It idles at 1.5k but when I go from a red light in first gear the bike is screaming but it says I'm at 3-4k
Title: Re: Non digital tach to digital?
Post by: Paulcet on April 18, 2014, 03:59:43 AM
Just one wire at a time.  Not both.  As for the wrap technique, does the manual for the tach say that it will accept that kind of signal?
Title: Re: Non digital tach to digital?
Post by: Blueknyt on April 19, 2014, 03:41:05 PM
some are inductive and take the signal from the sparkplug wire, others use the negative side of the coil primary as a signal. the instructions should tell you which.
Title: Re: Non digital tach to digital?
Post by: adidasguy on April 19, 2014, 05:18:53 PM
FYI: Our bikes have stupid controllers. The spark plug fires at the compression cycle and the exhaust cycle. It doesn't know whether the piston is in compression or exhaust, so the plug fires each time the piston is up.

Hence the pulses to the plugs are true RPM, not double nor half speed.
Title: Re: Non digital tach to digital?
Post by: Blueknyt on April 20, 2014, 07:07:34 PM
its the same system thats on 4cyl,  2coils with pos and neg firing spark plugs, a waste spark system. the GS just uses coils with only 1 secondary lead instead of 2.  you could drill and tap the head to fit 2 plugs per cyl and swap in the dual lead coils. but kinda waste of time for stock uses.