Small Engines (Lawn Mowers, etc.): No spark, regulator rectifier, spark note

Question
QUESTION: I have a Craftsman tractor model number 917.272220 with a Kohler 17.5 HP engine model number CV491; type number 27501that up until the other day was running great.  I pulled the mower deck replaced the drive V-belt and put the mower deck back on.  Started it drove it all was running fine.  The next day I drained and replaced the oil filter and refilled the crankcase with oil.  However when I tried to restart it the mower would not start (it is getting gas I confirmed that).  I check the plug for spark but no spark, I replaced the plug and check and recheck s still no spark.  I removed the Regulator, rectifier (15 amps) and replaced it with one from another tractor still no spark.  Note the Regulator that was removed was put in the other tractor and it started with no problem.  I have even tried by passing the seat safety pressure switch in case that went bad but still no spark.  Any suggestions?
Thanks, Tom


ANSWER: When you replaced the oil fliter, did you fill it with oil first?

Does the engine turn over?

---------- FOLLOW-UP ----------

QUESTION: I am not sure I understand your first question.  I refilled the crankcase with oil as noted in my original question text but did not pour oil directly into the filter because it would spill out when I turned it over to screw it on to the oil filter mount(if this is what you are asking).
The engine turns over quickly (new batter about 4 months ago)as in the pass before the no spark problem.


Answer
Most Kohlers you fill the filter then let it sit for five or ten minutes then install the filter.  Even though you have to turn it upside down.  By letting it sit for a few minutes it won't leak so much.  

If you have "Oil Sentry", not filling the filter may be preventing enough oil pressure to build which would.  I don't know if your mower has the shut-off or just a warning light, if it has "Oil-Sentry"

After that, on the coil, there is a small wire that attaches to it with a spade clip.  Unhook this wire and check for spark.  If it fires with the wire off, then you either have a safety switch or other switch malfunctioning.  If it doesn't fire, then you probably have a bad coil.

Try these and let me know what you get.  Thanks, PK.