Hallo Leute, thanks for replies! Actually a VHSB 37 is installed with original inlet pipe and reed cage. Sure it runs hard, but cannot stand to go far. Dare, sorry I meant at least >100Km with original fuel tank, this should be in the 5-6l/100km range. My idea.. or should call it hope at this point.. would be to consider to install this PWK 28 + vforce 3 reed cage I already own.. Sounds like an experiment to try.. I would have one adaptor machined for the reed cage and inlet pipe welded (for PWK 28 and PK 50 frame) I would think of an improvement in driveability in the 5000-7000 range most and lower rpm.. of course top end power and overrev would be weaker than actual state of tune.. Writing to see if anyone really using this PWK 28.. cannot think to be the only one this crazy.. :) Gruess, from "Hard headed" Matt