Flats machined on COX cylinder top fin, for the wrench

Thanks, Eric,

unless I can follow the method TexasWade was proposing, T am thinking of carefully fixing the 09 crankcase with one of  its mounting lugs in a vice (   ), and screwing in the cylinder in the crankcase. Then I will have the cylinder laid out horizontally, which is convenient for filing the vertically orientated fin.

For a mild force of filing the fin this should not require a strong grip in the vice which would be harmful for the crankcase nor its mounting lug. The backplate screwed in the crankcase adds to its rigidity to save the crankcase roundness too..

Just so that you are aware, I believe an English motor, maybe DC, recommended a strap wrench. They showed a drawing on it's construction that used a leather strap and a piece of wood for a handle. Pretty much like an oil filter wrench.

Thanks, aspeed, many fellow CEF members have also tried the leather strap method on COX cylinders, but I think only only a few managed to use it as a reliable cylinder removal tool...I am among those who were not successful. No matter how well I degrease the cylinder fins, and how tight I try to wrap the strap around the cylinder, the lil bugger  is just reluctant to budge...