tachometer is off

[00RangerShavedAndDropped]

i have a cheap little aftermarket tach that my friend gave me i hooked it in the wire off the coil and it seemed like it only read half of what the motor was really running and then i looked at some more forums and it said to tap it into the tan and yellow wire in pin 48 and i also did that and it seemed like it was reading double lol now i dont know what to do any help would be great

 

[graff104]

Does it have a switch on it for the number of cylinders? I know some do and that may have something to do with it.

 

[TomB1269]

Is it for direct ignition systems. Direct ignition fires on compression & exhaust stroke, therefore causing standard tachs to read 2x as fast.