Hi Mark2 I tried another test, I fitted a couple of fiber washers behind the points to move them out to a different contact area on the cam, this did even things up a bit so I contacted Distributor Doctor and he says he has several spare cams but could'nt guarantee how accurate they are, so the only way to check them is to send him my distributor and he'll experiment,so that's what I'm going to do. Thanks for your help and suggestions, very much appreciated. John