Well I finally decided to get serious about my 97 Aprilia RS 250 rebuild: Few years ago I had an engine failure with the power valves shattering into pieces and hitting the piston in the upright cylinder. Since then I took the whole engine out, stripped it down to the crank shaft and got it ready for the rebuild. Now, the cylinder where the blow-out has occurred doesn't look bad, there are few small scuff marks in the both power valve ports (barely seen and only felt with a fingernail), but none in the piston port. The bike has done 18,000kms. Im going to replace the pistons, rings, power valves, gaskets, o-rings, etc Do I need to hone the cylinder ports, especially, the valve ports and can they honed as they quite small, roughly 25 mm? Also, who can recommend a reasonably priced and trusted parts supplier from whom I may purchase parts for my bike. Regards, Andre
Always hone the barrel where the piston ring go to help them bed in. I don't know about power valves, mine only has ports.
Give the power-valve bores a hone using a brake cylinder hone. I have some good run in Suzuki Pistons. Only done a few heat cycles. Some of the proddy guys used to do this so on race day you didn't have to worry about bedding anything in. But if you want to buy new I go through mick hone motorcycles. They will send them out the same day usually. All Suzuki parts too.if you want a little more oomph order the sp base and head gaskets. A little thinner,will give you more compression.
