I have been told by mechanics at Bramble Mower (Great Guys) it is the carburetor. I am having it rebuilt, Not buying a new one. YET (350.00). Everything else looks fine. My hands can't do those little parts. Greg
Remove blower housing top of engine and remove all dirt & debris, take your time doing this procedure getting everything removed from vanes on heads, flywheel, etc. with shop vac or by hand, you will be surprised at the amount of crud buildup.
Notice this is an old post, but I'm having the same problem. Was there ever a definite resolution? I'm pretty handy, but not wanting to tackle any big repairs myself and certainly don't want to be guessing.
You would not walk into the doctors and say "I feel the same as the other guy" and to some extent mowers are the same
So exactly what do see see, hear , smell & feel when you turn the key ?
How old is the engine ?
What is it on?
Does the engine crank & not star ?
Does it fire a couple of times but not carry on"
Dose it turn over ?
Silly little things happen like not having enough oil so once the engine has been running for a while and oil is splashed all over the engine the oil level in the sump drops just far enough for a slightly out of calibration oil switch to trip & kill the spark, particualry if the mower was parked slightly up hill. ( A real life call out cost the customer $ 60 to be told to add 4 oz of oil )