Small Engines (Lawn Mowers, etc.): Briggs Model 460707 Diamond I/C 20 hp, fly wheel, carbon buildup

Question
I did put the two dots on gears to match for timing, it seems that I have no or very little compression.  would this be caused by a sheared fly wheel key?  I have spark.
Thanks.  Ed

Answer
Hi Ed
It sounds like the valves are not closing due to several possible things such as: out of adjustment, carbon buildup on the valve seats, bent valve or pushrod (if ohv). Check these things out. If the valves are not the problem, start looking at the piston and cylinder. With all that said, yes a distorted or sheared flywheel key can cause the engine to be out of time. Hope this helps.