Dude............................ If that's the reason. pull that thing off.... Spacers are only for applications where you need clearance and have to adapt a particular carb to a different manifold, like spreadbore carbs to non-spreadbore manifold.
Like Bill said said spray something flamable like carb cleaner or something.....NOT GAS. around the manifold intake and any hose hook-up point. Make sure no hoses have cracks. Check intake to head areas for leaks. Do you have pwr brakes?