Tough crud where vent plug gasket should be

[Jstep]

I went to change the gear lube oil in my 1969 pre-alpha Merc outdrive, and I am having a really difficult time cleaning the surface that the vent plug gasket should seat on. There is some sort of dark-grey/charcoal colored material in there that is very tough and stubborn. I have tried scraping it out with a screwdriver, pocket knife, and nail, but have not been able to get it very clean. My best guess is that someone had previously used some sort of adhesive sealant instead of the paper gasket. Anyone have any ideas how I can clean this stuff out??

 

[ErieRon]

Re: Tough crud where vent plug gasket should be

Tough crud you say? I hate that stuff. I had a very similar problem and it turned out it to be an old fiber gasket...Go figure. I would have sworn it was "tough-crud". Just use a small (pocket size) flat blade screw driver and scrape it off. Just be very careful to keep the blade at 90 degrees so you don't degrade the seat. Even if it is some kind of "space-crud", it's about the only way to get it out. If it was a sealant of some kind, now that it's cured, I don't know what might dissolve it.

Good luck.

 

[Jstep]

Re: Tough crud where vent plug gasket should be

OK, I used a smaller flat-blade screwdriver, like you suggested, and it worked. I had been using a larger screwdriver before, and the smaller pocket size like you suggested worked out better. It may have helped that I let the crud dry out a bit, too, because it seemed like it scraped off into more of a powder this time than a goop.