Trailtech Vapor Install on a 1998 Yamaha WR400 problems


I'm just finishing the Vapor install on my 98 wr400, I'm having some troubles with the tach when the unit is powered from the bike.

I have both grounds comming back to the coil mount, the tach wire connected to the splade connector on the coil and the power coming off the headlight

Currently if i leave the power lines disconnected, it works perfectly. But as soon as I hook up the Unit power, the RPM roughly doubles and becomes a lot more jumpy where as before hooking up power it was steady.

Anyone here have any ideas?


Try grounding the wires somewhere else, I done mine on the speedo bracket, its probably too close to the coil so messing up the reading.


speedo bracket? will that ground good?

I also tried running the power wires directly into the head light plug, red for power black for ground. Still the same problems


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