6hp Tecumseh horizontal compression issue?

I did a complete rebuild on a 6 hp Tecumseh OHH60 horizontal. Drained the oil and noticed some plastic pieces so I opened the crankcase and the governer gear was busted. I replaced that and dropped the valve lifters while I had it opened up and cleaned them. I put a new crankcase gasket on and closed it up. I removed the valve cover to take the head off. I cleaned up the piston head and valves, put a new head gasket on and closed it up. I never removed the piston. Cleaned the carb up, twice over. Tried to start it, it seemed to have very weak compression and would not turn over. I checked the plug, good spark but couldn't smell any gas on the plug or in the cylinder. To rule out some simple timing issues I removed the flywheel and replaced the flywheel key. I removed the valve cover and realized the valves didn't have any clearance, way too tight, so I loosened them up and set the proper clearance. I closed it up and tried and the compression was very strong. This is where I ran into an issue that I haven't encountered before. When I pulled the cord I could barely pull it through the compression stroke. I sprayed a bit of starter fluid in the carb and when the fluid got into the cylinder and I pulled through the compression stroke it and got an ugly surprise. It fired and yanked the cord back into recoiler but did not start. The spark definitely lit the starter fluid but I'm guessing something is messed up with the valves and the exhaust had nowhere to go. I'm sure I made a rookie mistake and I'm probably overlooking the obvious. I may still have a fuel deliver problem but I can't worry about that until I can get it to turn over correctly. Some help here would be greatly appreciated.