Guys,
I've got a newer 5" Sunpro III tachometer that I'm wondering if it works or not. Has any of you guys had one short out the ignition coil at higher rpms or anything like that. It also does'nt read the same as my old 3 3/8" Sun tachometer at higher rpm's. When I wind out my 390 pretty tight it goes up to 4800 rpm with the old tach. The new Sunpro III goes to around 4000 with the same engine noise telling me to shift. I'm using a pertronix igniter ignition system. Jim
It may be more susceptible to interference or ignition noise ? try moving the Tach wire away from any source of interference
Burns,
I called Sunpro and they said if the tach won't go over 4000rpm it's the Tachometer. They are sending me a new one. Jim