Lack Of Power Sportrack


Can anyone shed any light on my Sportrack 91 16v Carb model. I suffer from what I feel is a lack of power from a 1.6 16v machine, I live in a hilly region and find 5th gear useless and often find speed drops off on any minor graidient. Fuel consumption is high but that seems to be normal if I read correctly. I have checked timing at 800 rpm, spot on, replaced all vacum hoses, choke is not on, compression shows 165 psi on all 4. Plugs are black and I cannot get them brown. Was going to replace carb gasket and inlet manifold seal but cannot find supplier, can anyone give me some hints as to what to do before I have to get rid of it. John