Plating a 1980 RM400 cylinder

[Pantaz]

Nearly all of the engine parts for my 1980 RM400 are discontinued. I was fortunate to find first-oversize top-end parts from various local dealers. I'd like to keep riding the bike now and then, but if I have to do another top-end, I may not find parts.

My thought is to plate the cylinder, so I can get longer life out of it.

Question: If I plate the cylinder, will the stock ring seat?

 

[Rcannon]

I am not sure I would plate it. If you cannot find another piston, cylinder life is not an issue. Did you try Weisco? They still have an excellent piston selection for the 1982 YZ 250. If they have pistons, oversized will be no big deal. You should be able to bore it many times again.

 

[Studboy]

As Rcannon said, check with Wiseco. They make up to .080 overbore.