Trying to diagnose the new 'Burbs issues and get in running right. If I mash the throttle it backfires through the carb. What causes this? The carb is newly rebuilt, all the vacumn hoses are new. New plug wires. Timing is 8* per the emmissions sticker. Could it be the advance springs/weights in the distributor are worn and not advancing spark the way they should? I also ran a compression test on the thing today. Every cylinder was between 85-95psi. Is that good? Bad? So so? I kinda thought it was too low, but I know nothing about this kinda stuff. I'm pretty sure the mtoor is just way tired and needs a rebuild, still like to knwo this stuff just to know.