Very dissapointed in myself!

Steve Carlin wrote:

Admin wrote:I have burred two cylinders in the past, one from a Estes Black Widow and the other from an early Babe Bee. I have fixed both by taking a (trashed/worn) piston and placing it into the cylinder, screwing it onto a crankcase and then just slowly turning it over until it gets looser and looser. Once it was quite loose but you could still feel it "hanging up", I just started up an old electric motor with a rubber wheel on it and made it spin the engine over (while oiling the piston and shaft every so often). I looked at the cylinder every so often to notice the shiny dot in the corner of the port going away. After I thought it was even loose enough to start up, I hit it with some #0000 steel wool.

You don't want to use a piston to do this! Although the burr does "go away" as the piston goes past the spot, the piston is grinding on the cylinder on the opposite wall across of the burr thus wearing that spot down. This will result in case pressure loss and perhaps cylinder compression loss. There could even be more wear on the engine as the piston will no longer go up and down perfectly straight.

I would suggest sitting under a magnified lamp and using an Xacto knife to carefully remove the burr and then finishing it with Grade #0000 Super Fine Steel Wool.