Hi All thank for your offers of help/ suggestions. I've just come in from the workshop and as suggested the problem with the lubricator is a worn shaft. Despite being a 'commercial item' the shaft doesn't appear to have been hardened at all. I might take you up on your offer of photos Roger, but I'm going to Harrogate on Friday so I will have a look there first. I will try your idea of cleaning the regulator face tomorrow Ron. It seems to be a simplest way of doing it. Cotton wool has been suggested for blocking the ports to prevent the carborundum, dust getting into the cylinder so I will try that as well. I'll let you know how it goes. regards Andy MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.