confused

I have a 1977 omc outdrive behind a 351 ford.
Electric shift.
Boat & outdrive have 487 hrs on them total.
Have been well taken care of, fluids are fresh and checked and have been maintained in that condition since new ( I've seen the paperwork).

My question is.. twice ( two diff times) when I have shifted from reverse to forward and acc. hard I have felt a bump or two (like I hit a piece of wood) and then a kind of clunk like it went into gear. This has happened while the boat was picking up speed to get on plane.
The clunk felt almost like engaging 4wheel drv on a hill.

It never felt like it slipped out of gear, just like it went all the way in....... maybe.

Anybody got any ideas or know anybody to talk to?

Appreciate it.

smile

herm
_________________________
too much of anything is just right