I came across this thread by searching for the same answer a lot of others on here are seeking. After reading the entire page, I had to join to point out an observation in regards to rusyj14's comment that "Occasionally, the help doesn't work, mainly because the help seekers can't follow instructions" But, the fact is, the seekers Are following instructions. No disrespect meant, as I see many have resolved their problem with your help. But the others that are still at square one have done as instructed. They have repeatedly stated those instructions back, as to what they had done, but with no fix. And as you also mentioned for them to do, they Are here asking for help, but it seems their posts are going unanswered. From someone who at the age of 10, or younger, got his hands on his first lawn mower with instructions from his Dad to only tear it apart to see what was inside, with a Tecumseh that had sat out in the weather since who knows when, with a crankcase full of rain water, but defied his Dad and got it running to have it mow his grass for the next six or more years, I've been accustomed to getting things running. But having already done what all others on here have suggested before finding this thread, I am leaning towards the flywheel magnets having somehow lost their strength. It is the only part not bought new to replace. I thought I had read somewhere else that someone was able to compare the strength between a good set of magnets and weak ones by use of a fish scale and how much it took to pull away from it, but I couldn't find it again. I'll be completely dumbfounded if a new correct flywheel does not solve my issue either, as I've mentioned, it is the only part I have not yet bought to have everything brand new with regards to the ignition system. If I had a shop nearby that could magnetize it, I would go that route, but it will be cheaper to purchase a new one than to invest in the shipping and shop time to have it done.

Fish. ... The engine is a Briggs 128602. ... The head gasket is a graphite that looks REAL GOOD. ... I would order another one but my "Stens" book doesn't list it so I will have to call sears and wait about a month for it to come in. ..... The only way I see for the compression to get into the crankcase is past the gasket and through the push rod compartment. .... But the gasket sure looks good. .... Do you have any other ideas?... If the head gasket failed, wouldn't there be some sort of indication on the head or the gasket?. ... Thanks ........ted

There is only ONE adjustment screw and that is supposed to be for IDLE only. I do not engage mower blades at IDLE, only at higher RPM. The new coil is junk. Will have another new coil Mon or Tues. Now have intermitent spark on one side, weak spark on other side. Old coil is corroded through in one area. I'm still trying to figure out how most are saying it's a carb mixture problem when there is nothing to adjust, and idle speed isn't the problem. I still say it's the coil...we shall see. All this trouble over this engine and not getting much gardening done! Invested a lot in this machine. New blades, belts, engine parts, plus a new cultivator and hitch system. I need it to be working....just only so much I can do with little money. Very exasperated now. Neighbor down the road has 2 MTD riders for $50. Or 1 1/2 rather. Engines are different but still Briggs. No idea how bad those are...or if one of those would even mount since they are single cylinder and mine is a twin. 16 hp on the one I believe. Thanks for bearing with me on this and your suggestions.

@walt2002, hey i was wondering if you were still here, i have read many of your replies and was hoping to hear from you and mownie, you 2 seem to have a wealth of knowledge on these things, i will try the carb first, because it is the easier than the head, but how would the carb cause fire to pop in the carb? im no genius but it seems compression is coming through the carb, and with the few parts in the carb, even no diaphragm, i cant under stand how it would be bad, do they have a ball and spring behind a welch plug like the old model walbro carbs?, i remember years ago when i worked on them a rule of thumb was if you shook them and heard no rattle they were no good, it had something to do with a barometric pressure adjuster valve, you didnt have to adjust the carb in higher locations as you did a b&s carb, just wondering, because i cleaned the carb twice, i put it in a bowl of water while disassembled and used a small straw to blow air through every hole, got bubbles on all, but i will swap them anyway and see, i just want to know what it is, thanks for your advice man