Need help,Tach goes to 4000 rpm then rev higher goes back to 0..Checked all wires ok.I have gps with tach it work fine..Tach going bad ??

Maybe the motor turns off when you hit 4K??Are you sure it is still running?? Whats up? have fun in LOTO. Maybe check your coil if I had to guess.

REAl funny rob,Tach works fine on gps head so i don't like it a coil..