Only logical explanation is somebody filed the caps to “adjust” them. Don’t feel bad, that’s one of the first mistakes I made when I first started working on motors while still in high school. Part if the learning process.

You can cut some shims from brass shim stock to salvage the rods. If you can find somebody to sell you some shim stock without giving you a stare like you are stupid or something.

• This reply was modified 5 years, 7 months ago by frankr.

Might be easier to hone the rod bores that little bit? Just a suggestion. Might make them rounder again too.

Dan in TN

Earlier rods had a cast in bronze insert in the load bearing side. Testing proved the silver plated rods were stronger. I have used silver bearing solder on bronze that was excessively worn. Incidentally, honing does not guarantee a round bearing surface. To be really accurate you need a reamer.

• This reply was modified 5 years, 7 months ago by garry-in-michigan.
• This reply was modified 5 years, 7 months ago by garry-in-michigan.
• This reply was modified 5 years, 7 months ago by garry-in-michigan.

GG9120A is the Sea King equlivent. Frank, Reminds me of the old Chevy Babbit beaters Remove shims to remove wear. They had a 15lb oil pump.

You obviously have it apart. Be sure to replace the lower main bearing seal. Those motors were plagued by seal failure, which let water into the crankcase. Water and rust destroyed the silver plating and the remainder of the aluminum rod would melt and fuse to the crankpin. Most people would look at it and say it was an oil failure. Nope, it was a water problem, not an oil problem.