Mad Jack, Tell me if i am wrong What you mean is with the engine config your trying at the moment 6.5mm carb restrictor and 9901 pipe and so on the engine has plenty of power but more importly its useable power and also important more fuel econamy over the older novarossi engines?. On avarge with that config what run times are you guys getting from a buggy 125cc fuel tank?. Regards Jeremy.