Tachometer

[Redfisherman]

2004 Yamaha 90 HP 90TLRC outboard. Erratic or intermittent tachometer operation. This is an analog gauge, not digital. Acts like a loose wire, but checked all connections to the tach, no loose wire. I understand this signal is transmitted through the voltage regulator. Is that correct and what's the likely cause?

[99yam40]

signal should come from lighting coil output before the RR.
Might try operating the set switches on back of tach to clean up the connections in there