Jon:

You have been bitten by the famous OS liner shelling. And no, it was not cured four years ago, it still exists. But OS swears there never was a problem.

Even the new 46 AX series, that they proudly proclaim as Advanced Bimetallic Liner (ABL) is an ad man's way to obscure the fact that the "Bi" in "Bimetallic" still stands for brass and nickel. In words we common folk use, ABL is just another way to say ABN.

I will not buy another OS engine until they go back to chromed liners, real ABC engines. And maybe not even then, if Magnum keeps the quality that OS no longer has.

What you can do to repair yours, and get the quality OS left out, is buy the liner and piston set for the Magnum XLS 46. It fits, and it's true ABC. Also a lot less expensive than the shoddy ABN parts OS would sell you.

Before you order, though, check the rest of your OS. If any other parts are needed consider just buying a complete Magnum XLS 46. All new engine, high quality, and on sale for $70 from Hobby People.

Bill.