Hello,

I need to check the idle speed of my 2004 TRX400EX. According to the manual I need to use a tachometer, but it does not explain how to hook it up. I have a tachometer, but it was given to me a long time ago with no directions. Exactly which lead of the tachometer goes where on the ATV?

Thank you for the help!

Chip

Hey Chip, I wouldnt go so much by the manual, but more by ear and feel. Its not gonna explode or anything if the idle off. I would say one wire is to ground one to positive and the other probably tapped into the coil, or wrapped around the plug wire itself.

There should be three or four wires.
One positive for back light maybe a white.
One for ground power probably black.
One Red for positive 12V.
One trigger wire which connects to the ground wire on the coil. Coils fire by making and breaking the ground wire. Tachs count those pulses. There is usually a jumper wire or switch on the back of the tach to select how many cylinders for the multiplier.