29 minutes ago, Rack said:

Show a picture of your carrage bolts.  Do they have a square shoulder under the round top

In your photo it doesn't show that you counter sunk these. By counter sinking you get into softer wood so the shoulded will seat.

Note use a true counter sink bit not a over size drill bit,it will drift and oblong the hole.

Yes, the carriage bolt has square shoulders under the round head. Pic attached.

Correct, I haven't done the countersink yet with an oversize bit yet. I stopped my original install plan once I realized I was going to have this issue.

So, are you suggesting I kind of hammer that in to allow the square shoulders to dig into the wood so it will grip?

Not an option on my menu...

"Malivue diagnostics" is the last/bottom choice, and when I hit enter on that it just brings up the data stream.  There is not an "engine faults" menu choice of any kind like I have seen pictured on others' boats.

@RyanB, just FYI this thread made be actually check my transmission temps today as I was towing my tractor.  Around 90° outside today, 65 MPH, gently rolling Florida hills.  Transmission hit 208° going up hill.  I generally don't use tow mode or lock out high gears.

Can you make a short sleeve to use as an extension of the rivet gun head?  It should work fine if the gun will still grip the rivet shank.

Show a picture of your carrage bolts.  Do they have a square shoulder under the round top

In your photo it doesn't show that you counter sunk these. By counter sinking you get into softer wood so the shoulded will seat.

Note use a true counter sink bit not a over size drill bit,it will drift and oblong the hole.