I have a Toro model 20444 that I can't get to start. Here's what's happening to this B&S engine, model # 127802, Type 0640-01. Even when I pull the recoil, I can not get it to fire, other than an occasional/rare pop. I have spark, and know gas is getting to the plug. The pop indicated that I might have a timing issue, so I took off the top and found the key sheared. Replaced the key and put it back together. Also removed the carb and soaked it and rebuilt, as it was quite dirty with old gas.
Still no fire....so I grabbed a coil that I know is good and put it on, just in case the coil was going out. Put the coil from this mower onto another, and that mower works...so the coil is not the issue. Still nothing. Looking into the plug hole and can see both valves opening and closing. Pulled the muffler and can see movement of a valve shaft.
I've got spark, fuel, and air....I've tried three different plugs, including a plug that worked on a different mower.
I need some more ideas from the group please!