RPM Gauge Drops, but not Performance?

[readdad]

I have a 1996 Nissan 40 hp 3 cylinder outboard. I was out two days ago and when I reached 5000 rpm the gauge started dropping and finally bottomed out at 1000 RPM. The wierd thing is that when the gauge dropped, the motor never lost power or slowed one bit. Sound was good and never deviated.

I messed with the trim switch and when I hit the trim button the RPM gauge went right back to 5000 then slowly dropped. did not matter if I went up or down with the trim. What could this be? Bad gauge, bad wiring, idiot boater?

Thanks for your replies.

 

[pvanv]

Re: RPM Gauge Drops, but not Performance?

Likely poor connection in the wiring. The tach wiring may have an intermittent connection, probably back near the motor. A Factory service manual will show you the proper connection points.