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Just acquired a 1990 200, piston was locked due to head gasket leak, previous owner lost one of the kips valves. Can someone tell me if this cyclinder needs plated or bored out or is ok to rebuild and go?

Welcome to kdxrider.net.

You may want to try to clean it up, then take another picture. It looks plated, so boring is a no go. One can not bore a plated cylinder like a steel / iron sleeved cylinder.

Is the black the plating? Or should the black come off. The black comes off with a light scotch bright.

Green Scotch Brite and some light oil

Black stuff needs to come off.


Plating is dark gray / silver

Like above the black, the scotch bright should not be able to take the plating off.

Working by hand no the green scotch bright won't take off the plating unless there is a problem with it.

I don’t like those nicks in the deck surface


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david wrote:I don’t like those nicks in the deck surface

Me either.

Like has been said, clean it up and then reexamine the cylinder. You might get lucky but probably not.

Looks ok to me to at least make an attempt I have cleaned up worse. I use aluminum oxide drum rollers on a dremel tool or even a drill will work followed by red scotch brite on a drill as a ghetto hone.

The plating is way stronger than aluminum oxide and will melt away piston transfer material in seconds and leave the plating untouched. I have actually tested this trying to go through the plating and its not possible. After you finish you can put some muriatic acid in the cylinder if it dont leave a mark/smoke ( be careful around the ports!) the plating is fine and can continue with the top end rebuild and not second guess it.