As I'm rebuilding my water pumps on Yamaha F250 & LF250, I noted some rough build up that looks like caulk on the inside of the impeller housing. Both housings have this in the same place. It is not crustyvlike salt, very much like a caulk that was smeared. This has me stumped. Any ideas, is this common? This is the first time I've done these engines.
Randy
Randy