Hello all, thanks for all of the information as I've been reading the forums for quite some time, but this is my first post. 2006 Sea Ray 340 with 8.1's. After starting the starboard engine and idling for a couple few minutes, Smartcraft will emit a single beep, the starboard engine will surge from idle (650RPM) to about 850RPM, then return to idle. At the same time, the Starboard engine tach ceases working. Both the mechanical tach and the digital display 'die'. Mechanical goes to the 0 stop, while the digital display shows dashes. I need to verify today, but I think the depth indication also goes to dashes, but all other data remains good. The engine runs fine without the tach indications, and almost always the tach comes back alive later in the day. If I shut down the engine and restart, the tach works fine, until the tach decides to resume the above behavior. I've checked connections behind the gauge, but guessing with the 200RPM surge it is not a connection issue. Any ideas? Thanks!