Small Engines (Lawn Mowers, etc.): Tecumseh OVXL120 lawn tractor engine not starting, spark tester, compression chamber


Question
Hi John, my engine is not starting. The engine just swings and air seems to be coming out of the carb. (from the air intake section) rather than being sucked into the compression chamber. The plug is dry no sign of fuel. I have done the following already with no luck:

1) I adjusted the intake/Exhaust valves clearance: .004in/.008in.
2) I checked the compression: I turned the flywheel counterclockwise and there is kickback even with the push rod on exhaust valve removed.
3) I checked the ignition coil using a spark tester. Spark seems fine. However I have noted a slight brake in the cord from the coil. I also disconnected the ground wire and there is spark.
4) I checked the flywheel key which is ok.
5) I put a few drops of fuel in the head and put back spark plug and nothing.

Any idea what the problem might be???
Thank you

Answer
First, I would put it back together, and leave the air filter off, and squirt fuel into the carb
and try to start.  If it starts then dies, then you know it is a fuel problem, if it does nothing, then you have a compression or spark problem.
   If the fuel mix comes spraying out the carb, then you may have a loose seat in the head,
and compression is leaking into the carb.  If the seat is loose, I have peened them back in place
and recut the seats with success before.
  Also, another possibility, is that when checking the key, if the nut was not re-torqued properly, it could have sheared after, and your timing is off.
   Check these things and let me know..