Marinette Boat Forum

I hope your battery tested for more than 12V.

A 12-volt battery should read between 12.5 and 12.7 volts when it isn't being used. A 6-volt battery should read between 6.25 and 6.35 volts. Anything less than 12.5 or 6.35 volts indicates your battery needs to be charged or replaced (if its charge depletes quickly).

Not saying this is the problem. but how many times does an electric problem on a car result from a bad battery which one thinks is ok?
CapnGary

symptoms suggest weak connections as Karl hints. Check for corrosion, loose connections as first step

The toggle switches used for ignition on Ms, and many other boat, do not hold up as well as a high amp switch (like a key switch, push button or heavy duty toggle). I bet 90% of the starting and running issues I have seen in boats with the plastic switches are because of the switches. Voltage drop tests are a must.