I have one of the above, and after abut 5 or 6 uses the generator clogs up. I have been through about 3 now, and at about £18 a go is getting silly. I use Coleman fuel, and follow all instructions rigidly. I always run the thing for at least 5 mins to (hopefully) clean out any carbon. I have cleaned out the tank, and anything else that may be blocked. The usual is that with a new generator it works well about 4 times, then burns very badly, then when you pump it up and open the valves nothing happens. With the generator removed fuel spurts from the tank as it should. I also have a smaller version (a 442 I think. It uses the same generator) Exactly the same thing happens with this. I have met people on campsites who are using them, and have asked for their advice. They show me how they light them and use them and it is identical to what I do. They say they even use unleaded petrol on them, and say they have been using the stove for years without any problem. They even say that they frequently run the thing for aminute or 2 just for abrew. Any ideas on what I am doing wrong, and are there any methods to clean out generator tubes.