"I think as Jeff says, a froze
"I think as Jeff says, a frozen valve or very loose valve adjustment are the primary reasons for bending pushrods, I have done a pushrod before in one of my engines when it got a gut full of water in one cylinder. When you stick an engine in a marine environment I think you have to sometimes think outside the square a little, water being an incompressable substance, if you get a gut full of water, things can bend.
Thats why I asked about the posibility of water in the cylinder.
But the fact that your plug came out black would discount water.
Although very unusual I have also seen Hydraulic lifters lock up in a compressed position and spit out the pushrod so you should check to see if you can colapse the lifter as well as move the valve if she is fitted with hydraulics.
What ever the cause Crabbie you have some investigating to do.
Cheers
Peter c"