I always take the cylinder to the Honda dealer or local ATV shop and get it bored to whatever it takes to clean up the scratches and then get the over sized piston and rings and gaskets to match.
Ebay might have a kit you can buy, I know they have the kits for the 350 Rancher. You just have to send your old cylinder to them and they will send you another cylinder already bored and the new over sized piston and rings and gaskets to match it.
And no, you don't have to do anything else to the engine other than getting the cylinder bored and the new over sized piston and rings and gasket to match. Although, I would get a new piston pin and clips, like 69 mentioned above, and check the rod bearings. Grab the top of the rod where the piston pin goes, and try to move it up and down. If it has any up and down movement, then your rod bearing is bad. A little side to side movement is normal.
Ebay might have a kit you can buy, I know they have the kits for the 350 Rancher. You just have to send your old cylinder to them and they will send you another cylinder already bored and the new over sized piston and rings and gaskets to match it.
And no, you don't have to do anything else to the engine other than getting the cylinder bored and the new over sized piston and rings and gasket to match. Although, I would get a new piston pin and clips, like 69 mentioned above, and check the rod bearings. Grab the top of the rod where the piston pin goes, and try to move it up and down. If it has any up and down movement, then your rod bearing is bad. A little side to side movement is normal.
