Accepted Answer

Hi Kevin

The votage regulators do burn up on these motors, some for no reason but on occasion running the motor with no where for the charge to go (battery disconnected or isolation switch knocked to off position.
If your trolling motor has a high draw it may pay to call the manufacture and ask what the draw is and install a fuse for it to further protect the rest of the charging system.

The tach takes it signal from the same regulator box so most likely related to the failure.

Your motor has a speedo pick up built into the gearbox, on the leading edge about half way from the nose of the torpedo and the cavatation plate you will find a 2mm hole, you will find that if you have struck a bit of drift wood or other debri it will have blocked this hole, get a small drill bit to clear it out.

Your motor is 2-stroke all the time and drops the bottom 2 cylinders below 2000 rpm.

Hope this helps

Grant