Jhehaz

Thanks. I know the filter is ok, not sure about the other things you mentioned. I suppose it could be running rich, would this cause the plug to overheat and die or something like that?

Nothing actually blows, the engine just stops and wont start again until I fit a new plug. The electrode looks ok, a little black and slightly oily/sooty but nothing really unusual...

I have the same bike (not the same one but the same model etc) and the plugs only last about an hour and then suddenly die. It is quite expensive and annoying, any ideas gratefully received... apparently this is a common problem with these machines?