Adding a tach to MY 250 D-Tracker
 

My bike didn't come with tach and I might want to add one or a rpm actuated window switch device to help me in testing. Which would really simplify things with a timer starting at a specified rpm and stopping at a specified rpm :)

4200-8500rpm testing for example: starting with say holding 3rd gear @ 3890rpm (20 mph), then WOT - the window switch turns on timer at 4200rpm and turns it off at 8500rpm (44mph) (with my gearing and rear tire diameter) I tested my speedo with a speedometer app and it's slow 10% but I could allow for it that.

Simple 1 gear test bursts. As long as I use the same stretch of road, the comparison timing from one mod to the next would be valid and quick.


I think KLXs with tachs have one wire to the coil and one to the CDI. I'd rather not be connecting anything to my CDI, so I wonder how people here have hooked up the Vapor or Trailtech?

I suppose if their bike OEM cluster had a tach they just used factory connections, but if something else was done I'd be interested

Is the KLX250 ignition a capacitive or inductive type system?

I know everyone refers to it as CDI but I need to make sure


TIA

vapor
 

Hooked my vapor to blue wire from coil, was replacing existing speedo tho and hooked into that harness. Vapor comes with more than one way to hook tac up. You can go on there site and see how.

I'll take a look at the Vapor website then, thanks

Richard, I'm not really familiar with the D-T, but the wiring harness may have the same OEM tach wire as the rest of the lineup. If it does, locate it on a wiring diagram and use it like I did for my Vapor. Just like mod40, my '06 was a blue wire. On the other method that Trial Tech shows on their site, I tried variations of that method, and it was somewhat unreliable. When experimenting with that method I read some sources of people using a resistor or diode or some such setup to get that method to be more reliable, but for me it bounced around on the readout too much.

I'm in communication with MSD about their window switch. The tech guy said their box would have to get a signal from the coil, and asked how many primary wires there are and if it's capacitive discharge.

I sent him Pippin's wiring diagram, but i guess I'll have to pull the tank and see if there's 12v at the primary with the key on

I can answer that: the ignition system *is* CDI, and there is no dc voltage at the primary with the key on. The CDI box sends a negative 140V pulse to the coil for ignition.

Ah good, thanks Ray

For what it's worth, I had to design a special circuit in order to get a square wave signal from the coil. I needed that signal for my cruise control. This is on a 2006.

Ron :D

MSD says if I use their GMR pickup (part number 8918) it 'should work'.. for what I want to do