Sticky screw on Yamaha 9.9

[nmccubbin]

One of the two screws that clamps our Yamaha to the dinghy transom has been stiff since it was new in 2006, and gets stiffer every year, despite plenty grease and no visible corrosion
Can’t take screw out without cutting one end off

Any solutions?

[pcmm]

Try using something like PB-blaster to loosen things up