Reply To: Evinrude Model R locking transom clamp

[PM T2]

The inner part of the lock is probably die-cast zinc. The zinc alloys of that era were very unstable due to tramp elements (aka contaminants) being allowed to build up in the molten zinc furnaces.  in most cases, the culprit is lead, as the standard created in the early 1930’s states that lead can only compose less than 0.003% of the alloy. In the late 1920’s, it is known that the alloys often contained lead contents of more than 1/2 of a percent, which leads to the breakdown most often seen in Tillotson carburetors in the 1927-29 era. The cracking you see is due to a phenomenon known as “intergranular corrosion” that causes the original casting to start to wander from its original form by growing or “creeping”. There isn’t likely a way to get that cylinder out without destroying it, but keep in mind its already basically destroyed, it just can’t show you how bad it really is. Tom Manley wrote an article in the Antique Outboarder that was printed in the January 1992 issue of how he dealt with a seized up lock cylinder and how he fixed it using modern parts to make the lock functional again. The number on the lock might correspond to a code that allows a locksmith to make a new key, but the innards are going to be jammed up so I doubt even the proper key would get the lock to work again.

Hope this helps.
Best,
PM T2

He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...