engine will turn over but not start. it is getting spark and gas I checked coil, replaced plugs and distrib. I checked timing and firing order. Since there is spark and gas shouldn’t I at least get a backfire?
Is there a story; like something happened the last time the motor was running? If you are absolutely certain you have gas and spark, then the missing element could be compression. Valve timing is important and if the valves are open during the compression stroke, even just a little bit, you won’t have enough compression for the fuel/air mixture to ignite.
It was running fine until we pulled the distr. but we have reinstalled it 3 times and are certain it was aligned correctly when we put it back, each time. maybe the fourth times the charm.
When you replaced the distributor, are you certain you got the wires in the right order?
Also, check your timing adjustor (driver side fender, next to the gray metal rectangular box) - you may have to adjust it to change the spark timing.
If it was running fine, why did you feel the need to remove the distributor?
Remember that in a four cycle engine TDC occurs twice, once on the power stroke, and once on the exhaust stroke. My guess is you have the distributor set up so the spark is occuring on the exhaust stroke.
Did you put witness lines on the distributor before removing it? Did you rotate the crankshaft while the distributor was out?
The Vigor’s spark timing isn’t based on distributor rotation. It has a separate timing adjustor that you turn a screw on to adjust timing.
Generally distributors have one side of the crankshaft tab larger than the other so that you can’t install them 180 degrees off, though I have heard anecdotes of people managing to do so by forcing it on and shearing the metal.