Hi all - I just got this motor. It ran fine on old, and I suspect, lower octane unleaded. I put in a new high micron rated fuel/water filter seperator (CAV Delphi), new fuel line and fittings. It ran fine before I did all this. I then went and put a belly full of 98RON high octaine unleaded in and out I went. Ran beautifully cold and hot on the plane, but brought back to idle it missed every few seconds but did not stall. I have a feeling that the high octane might be responsible. To hedge my bets, has anyone used carby cleaner in fuel with any success?<br /><br />Cheers all ![Confused :confused: :confused:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)