I have a Briggs 22hp ELS725 v-twin engine on a Craftsman GT5000. I bought it at an auction. So I know nothing about its history. It will only run on the right cylinder. If I pull the left plug wire I notice no difference. If I pull the right on it stalls.Things I have done so far:Checked for spark. Yes it has spark to the cylinder.Adjusted the valves.Changed spark plug.After that, I pulled the head and looked for a blown head gasket. It looked good. I replaced it anyway. Adjusted valves again.Ran compression test. 100 lbs of compression.Checked flywheel keyway. Its good.Changed the magnetto/coil anyway. (pulled the kill wire, just in case)Changed the carburetor and complete intake. (just in case the plastic intake was cracked)*All parts used were from a known good running engine.What am I missing?Model 40H777Type 0241E1Code 030411YG