Will a 48mm piston work in a 49mm steel sleeve cylinder?

[Chainlube]

Those deposits on your head are probably from mixing in the tank, some of the oil settles out and makes the mix rich here and there. If you have a little jerry can and mix it up in that, I bet a lot of those deposits go away. What does your plug look like?

 

[CuriousJojo100]

Those deposits on your head are probably from mixing in the tank, some of the oil settles out and makes the mix rich here and there. If you have a little jerry can and mix it up in that, I bet a lot of those deposits go away. What does your plug look like?

First pic is after I completely cleaned the top of the cylinder and ride 40 miles with it running like it was lean.

 

[CuriousJojo100]

Will I do any harm by removing some metal from the upper lips and the lip that is opposite of the exhaust port? (Cylinder is upside down)