Hi, I've got one very similar, came with a Rotax 637 engine, but I've currently got a Piaggio twin-cylinder engine fitted, as I'm struggling to get the Rotax running. Not that the Piaggio engine's any better currently, can't make it tick over- revs out nicely, but will NOT idle.. Any pictures of your engine/ jet unit etc, and if you can shed any light on the tickover problem, I'd be grateful!! Cheers, Tim.