Upon removing the spark plug in my son’s kid kart engine, the cylinder threads came with the plug. I put in a full thread insert. The engine ran good this past weekend. I pulled the plug after the weekend to check color and the thread insert came out with the plug. The cylinder is a “B” size cylinder. I have a brand new “B” size cylinder with good spark plug threads.
Can I swap cylinders without changing pistons?
Can I set the base gaskets the same and be close on CC’s and port heights?
The short answer is yes, you can swap the head without changing the piston as long as you are switching an “B” head with a “B” head. It would be a good time to replace the top ring while you have the head off. As far as your compression and port heigth, there is no way of knowing for sure without checking it. You can certainly just swap the head and the engine will run just fine, but you may not be legal.