Tecumseh Help Needed

I have been trying to get an HS50 (5hp) on a snowblower that has set for a few years running. It had no spark when a I got it. I put new points and condenser on it checked timing. (points and coil inside flywheel) It would then only start and run at idle. I soaked and put a rebuld kit on the carb. Checked compression (60 psi ) the removed and cleaned both valves, lapped them and set valve lash back to spec. The engine will still only start at idle after alot of rope pulling, after it warms some if you slowly increase the slowly it will rev up and run. If you engage the the blower or increase the throttle fast it will back fire through the carb once then either rev on up or die. I am to the point of taking a match and checking to see if there is any gas in the tank (lol). If anybody has and ideas please your help will be greatly appreciated.:banghead3