1998 Mercury 30 hp 2 stroke outboard - electrical problem

Question
Hi, I have a 1998 Mercury 30 hp, 2 stroke outboard motor on a Smokercraft boat.  The engine has electric start and power tilt with separate oil reservoir.  The boat has tachometer, speedometer and volt meter on the dash.  I have been experiencing the following problem.  Heading out on the water all seems fine, but after 15 - 20 minutes the tachometer and voltmeter gauges start acting erratically.  The voltmeter will swing completely to the left and vibrate and move back and forth.  The tachometer will also move erratically but not to the same degree.  The motor seems to run properly and sounds the same, when this is happening.  In some cases, all will stabilize and operate fine for a while and then start acting up again.  The outboard has been serviced annually at my local marina.  Any ideas?

Thanks Dave
Peterborough, Ontario

Answer
Hi Dave...thank you for selecting the undesigned to reply to your question.

Although I'm not a mechanic, sounds to me like the alternator or coil may be acting up. Have you tested the battery's amperage, rather than depending upon the in-dash volt meter? Best you get the problem analyzed by a professional. It may cost less in the long run at this stage, and possibly more later.

Safe Boating
Ron