Hi Grumpy. ( still unable to upload photos due to previuos problems, Bruce is still looking into it) The saw is a Shindiawa EC7600. Havent reversed the hoses as they are of different sizes and a primer can only work one way. The carby I have got is similar to the picture you supplied but it has 4 hose connections on it, one on top which goes to the crankcase, one on the bottom which goes up to the air filter casing, one for fuel in and one for fuel out to primer. Try to explain whats happening a bit clearer. Connect fuel hose to inlet on carby and primer hose to carby, pump, get no fuel. Connect fuel hose directly to primer hose,no carby, and get fuel within a few pumps... There are no air leaks or split hoses to be found.