Installing tachometer

Discussion in 'Sportster Models' started by rmarshall234, Aug 17, 2012.

  1. rmarshall234

    rmarshall234 Member

    18
    11
    0
    I want to install an aircraft tachometer (it's a nice one and it was free and I'm a pilot) on my 06 sporty. Can anyone tell me what lead to use for the "signal" wire? Is it the LGN/V wire listed as Databus/Datalink? It's a three wire tach.....battery power, ground and signal. The first two are easy, just not absolutely sure about the third.

    Thanks!
     
  2. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    4,316
    73
    130
    Cant answer your question exactly but the data link isn't going to work for your signal lead. You need to find a wiring diagram for your bike to be sure.
     
  3. rmarshall234

    rmarshall234 Member

    18
    11
    0
    Thanks for the response. I do have the manual and schematic...

    The lead going to the 1200 version that does have a tach (mine's the 883 w/o) is the datalink lead. The other leads seem pretty clear....ignition, accessory, ground, etc. I would expect to have a lead coming from the coil, just wondering if they are calling it the datalink lead instead - once the "brain" sorts things out. Maybe I need to go right to the coil to pick my signal.?
     
  4. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    4,316
    73
    130
    I believe the "datalink" is HD's communication bus. Not sure what language it speaks. It would work with their "HD datalink" tach. Since yours is of the normal (read as old school) tach, I think it would be better to run your own signal wire from the coil. You know it will work that way. If you use the "datalink" it may not work but worse yet, kill something else....................
     
  5. rmarshall234

    rmarshall234 Member

    18
    11
    0
    Yes, good advice. I don't want to let the smoke out of _anything_. I'll pick up a signal from the coil, and all should be good. Thanks for the help!
     
  6. voodoomaster

    voodoomaster New Member

    4
    0
    0
    Your Sportster is a single fire ignition. Hooking up the tach to one coil lead will cause your analog tach to read 1/2 the crankshaft RPM since your only connecting to one coil. You need to use both coils for an input, meaning your gonna need a tach adapter.
     
  7. rmarshall234

    rmarshall234 Member

    18
    11
    0
    Does the same hold true if I'm using a digital tach instead of analog? And what is a tach adapter? Thanks.
     
  8. Hoople

    Hoople Account Removed

    7,198
    0
    34
    I think your working backward. I would first research how this tach is triggered in an airplane environment. Then you will know what to supply to it in order for it to work correctly in any other environment. There's no telling what an airplane tach needs for a trigger signal.
     
  9. marknett

    marknett Active Member

    205
    0
    1
    I thought sportster 's were dual fire unless converted .If it is single fire then you would need to get adapter

    on digital tachs , you can select dual or single fire in the parameters so you would not need an adapter . The adapter hooks up to both sides of the output coil and sends the signal off each side as it fires . If you are running a dual fire (both sides fire at the same time ) which is how harley usually does it , you can just pick up off the hot side of coil
     
    Last edited by a moderator: Nov 9, 2012
  10. cromedome

    cromedome Active Member

    264
    0
    3
    Most aircraft tachs only read to 3000 rpm, and the Sporty will crank up a lot more RPM, whats the scale on the tach?