I have spark at the plugs. All new tune up parts. Timing is set with slight advance with cap #1 just to the right of rotor when at TDC. The rotor is turning. Points and plugs set to MFG spec but off the top of my head I cannot remember. All new fuel lines, tank, fuel pump. Fuel bowl in carb is full when the top of carb is removed. Accelerator pump is working when the throttle is opened. I could not get it to fire even with ether. That is why the vacuum question. Could a huge intake leak cause similar symptorm?