Stripped the carb down on the Pennzoil Super Chipmunk and cleaned it out. Refitted and the engine started but would not run above fast idle and then die. That's something at least! Took the top regulator cover off and found fuel on the atmosphere side. Damn! Today, Saturday some Walbro carb kits turned up so engine off, carb off again and fitted new diaphragm and flapper valve. Refitted engine and away it went. The diaphragm must have been perished but I could not find any holes in it by holding it up to the light. Oh well, all sorted now.
Now when is the nice weather returning?