I have a 4 year old Simplicity Conquest with 190 hours. It has a Briggs and Stratton Vanguard two cylinder engine. There was nothing wrong with it. I used it to roll our 4 acres of mowed lawn with no problem. I changed the oil and the oil filter and drove it on low RPM about 50 yards. Tried to start the blade on the low RPM and it spit and sputtered and stalled. The mower has an oil pressure switch and the oil pressure light lit on the console. I checked the oil and it showed one quart low. There was no oil leaked anywhere. I pushed it to the garage and went out the next day, checked the oil and it was full. Thought it may be a bad filter, you never know, and got a second one and changed it. Ran for about 30 seconds and quit.
There is no smoke, and it never got hot. There is no gas odor. The oil has a radiator/cooler about the size of a sandwich. I am mystified. What am I missing? Is there some type of switch associated with the auto shut off that I should be resetting? HELP!!
You need to read & familiarize yourself with operators & engine manuals. PTO is to be engaged only when throttle is at full or max position. Check fuel & air filters as well as spark plugs for replacement. Use B&S OEM parts, example: oil filter, fuel & air filters, spark plugs etc. only for your Vanguard & it will give you many years of good service. Also check oil level on dipstick before & after each use & adjust as necessary, use only high quality synthetic grade oil in engine as specified in your engine manual, I prefer 5w30 full synthetic Valvoline or Pennzoil in my Vanguard. Post your 7 digit Simplicity model number, thanks.
Get the manual and check the wiring very carefully.
I have come across this problem twice so far and both times it was a wiring plug that had been disloged during the service.