Are you serious? Definitely do not try to get the engine started in this situation. If you do get it to fire, you will destroy your lower-end bearings. Fuel has filled your cylinder and crankcase and caused a hydro lock. Shut off fuel flow. Drain crankcase and replace filter. Find out why the carburetor needle can't hold back the fuel pressure. And put new oil in it.

OK, I see in the IPL that item # 238 (Briggs # 691843) is the cap you referred to. Thank you for outlining the part about "holds 80 psi". Now that you have confirmed what I thought you meant, I need to ask, is 80 psi, the pressure you are applying to the cylinder (I presume you have an adapter air fitting threaded into the spark plug hole) with an air compressor, or is the compressor SET AT A HIGHER psi........and 80psi, is all the cylinder will maintain? I hope you understand what I am asking but let me put it another way. While you have the source of compressed air connected to the cylinder, does the air compressor cycle on and off to rebuild air that is leaking off "somewhere"? If the air compressor DOES cycle on and off, but you don't have any air leaks in your compressor air hose or plumbing, then the air must be leaking out of the cylinder somewhere. An "air leakdown test" is not simply to connect air to the cylinder and see how much pressure the connected air compressor is capable of maintaining (on the gauge). An air leakdown test must really be done with a gauge that "measures the PERCENTAGE of leakdown, even a "good cylinder" has "some leakage". It is neccessary to determine if the "actual leakage" exceeds the "allowable volume (%) of leakage" An air leakdown test is also conducted to determine WHERE the air is leaking from (valves? piston or rings? head gasket?). So, your answers to the questions of just how you are achieving the "80 psi for 30 minutes" will allow us to get past that issue as you may well be getting a false indication of "health" from what you have been doing there with the air pressure. During an air leakdown test, you should be listening to for air escaping into the exhaust system, or the intake manifold, or into the crankcase. Of course, the crankshaft must be stopped at the correct position AND HELD there so it cannot turn when the air pressure is applied to the cylinder. To "listen" for escaping air, I use a 2 foot length of plastic tubing (5/16" or 3/8" diameter, at auto parts store or plumbing supply). Place one end of the tubing into the muffler or exhaust port (if muffler is removed) and hold the other end close to your best ear. Any air leaking past the exhaust valve will be heard through the tubing. To check intake valve, place one end of tubing into the carb throat (with throttle wide open) or intake port (if carb is removed). Air escaping past the intake valve will be heard through the tubing. To check for air escaping into the crankcase (because of piston, rings, or head gasket defects), take the oil level dipstick out and listen for escaping air coming from the dipstick tube, or you can hold a small "flap" of tissue paper over the open dipstick hole, if significant air is coming out of the dipstick hole, it will lift the tissue off the hole. Wipe off the dipstick hole before laying the tissue in place so it won't just "stick" to any oil. OH YEAH, please post here and ask Mr. Walt Conner to post his "cryptic" e-mail address so you can contact him for HIS instructions on adjusting the valves. Walt is one of the primary Briggs contributors on this forum and most times Walt's instructions are better than Brigg's. It would not be "proper" for me to "set you up" with his e-mail as Walt has his own way of handling that. However, if you search in this forum and find a post where Walt "furnished" his e-mail address to another member, I'm sure he would be OK with that. It's just polite and PC to "ask first". Here is a link that might be useful: 313777 IPL

I just read this and it sounds to me like it may well be the woodruff key in the fly wheel that sits on the crankshaft has moved a little or even snapped......Some times as you mow and it say hits a bit of wood or comes under heavy load that key can move a little or as i say snap. Then when you try to start it you may get a kick from the starter pulley like a horse kicking you in the arm...I would take the top pulley off and the NUT then look down and see if the KEY is in line with the pulley SLOT. If its slightly off line even 3 or 4 mill of line i would take the flywheel off and renew the key or check it and reseat it....It may be some thing else but if you have tried every thing and it still kicks check that..Its quite common...It just put the timing out a little........................................I have a 6 year old Sears Craftsman lawn tractor with a 24 HP OHV Briggs & Stratton engine. When I was moving the lawn the other day I heard a "pop", then the engine died. Now when I try to start it the engine kicks and backfires, but never comes close to starting. We checked the fuel and the spark and both are present. I can't help but think if it died suddenly, and now is backfiring when I try to start it that it must be something related to the timing. Unfortunately, I don't know anything about how the timing works on that engine. Is it possible the timing chain/belt (if it has either) could have jumped a tooth? Any other suggestions for what this could be, and how we would go about diagnosing?

Well that would be a 31 or 33 series engine, doesn't really mater in this case since they are basically the same design. Extremely unlikely cam has gotten out of time unless you removed the sump. I have two suggestions, I can send you Detailed Instructions on adjusting the valves and or a Service Manual IF you like. Address below, put in proper format and remind me engine model number and what you want. Walt Conner wconner5 at frontier dot com