Penta 275 outdrive prop ate the rope couple screws snapped

[jmok1978]

This weekend my prop ate the rope while i was on the tube, wife and son didn't keep an eye on it as they were pulling out the slack. I spent 20 minutes pulling all the rope out and the boat continued on the rest of the weekend without problems. After pulling it out today I noticed the prop made a funny sound when I turned it by hand, turns out it was the two screw outlined in my photo below had broke and they were rattling around in there. Looks like I am going to have to try and drill them out.

Anyone know what the part number is for these or what the screw sizes are? I can't seem to hunt them down.

Also, any tips on drilling these out?

 

[jmok1978]

Now I am thinking that what happened is there is supposed to be a zinc anode ring there, there wasn't. Maybe this ring wore out over time and fell off? And then when the prop ate the rope it snapped the screws? I think I am supposed to have the part in the pic in the attached image. There was no plate, just two screws that look like the ones in the pic.

What the heck does the zinc anode do?

 

[dubs283]

What the heck does the zinc anode do?

In essence, science

The anode is present to enhance catalytic corrosion upon itself. It's sacrificial as in it deteriorates sooner than the drive itself.

The anode's inherent design is to corrode.


Fresh water use only requires magnesium anodes, salt water requires zinc. If you're 50/50 salt/freshwater aluminum is acceptable