Sportster Tach Jump and Stall

Q: I was coming home from Chillicothe Easyriders on my 1998 1200 Sporty when the Sportster tach jumped around, and then stalled. It started again, then maxed out and the bike died…..any ideas where I should start? The tach was fluctuating wildly while the engine was running smooth. Then it would sputter until the tach buried itself past redline and the engine died. It turns over fine but won’t start now.

-Thanks, Brock

A: Brock, Try disconnecting your tach. When a tach goes bad it will usually “confuse” your coil and create the problem you described.

Feedback: Well, I disconnected the tach and it fired up, warmed up, went up and down the block and sputtered & died again. .. ?//?? what next bros?

A: First, check the condition of your spark plugs and spark plug wires for something simple or obvious. Next, use a multimeter to test your coil. Disconnect all wires from your coil. Set your meter to ohms. Test the primary side of the coil (the 2 posts where your ignition wires go). Attach one lead to each post. The meter should read somewhere between 2.5 to 3.1 ohms. Then, test the secondary side of the coil (where the spark plug wires plug in). Place one lead in each socket. The meter should read somewhere between 10k to 12.5k. If you have readings above these, your coil is bad.

Feedback: Hey man, I just wanted to get back to ya and say THANKS!!!! It did turn out to be the coil. I’m back on two wheels and I sure appreciate your help!

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7 Responses to “Sportster Tach Jump and Stall”
  1. Edward J.

    Any idea where the wire for an after market would be , I’ve got a 2004 Heritage Softail 88 ?

    Reply
    • Customer Service Techs

      Hi Edward. We would like to help, we just need a little more information. What exactly is the issue and what are you trying to accomplish?

      Reply
  2. Mark

    I have a 1986 Classic wanting too put on a Speedo an tach the four wires coming off the tach I’m not sure what goes where some help would be great

    Reply
  3. don call jr

    i recently modified my right side cover.i had cams come out with it. finally got it all back together and had to advance time all the way up to run good .do i have time out.need ur help. 1997 hd 883hugger
    sportster .thanks

    Reply