Yes ewalk, I was referring to the products with outlandish claims to get people to buy it. Products that swear to rebuild your entire engine with just one 12 ounce bottle added to your crankcase, or say you will get substantially better gas mileage instantly. Sorry to offend you Sax. I didn't know that you had Dura Lube, Sham Wow and Leak Ender stock. As for E3 spark plugs, I have tried them and have not seen any great improvement. If you have a starting problem and an E3 made it better, well good. Most likely a hotter plug of the same brand as the OEM supplied would have done the same thing for half the price. But if it was quick and easy and worked, great. Most of us won't miss a house payment over a $6 spark plug. I have a set of Split Fire plugs in my wife's car right now. Why? Not because they work better or make a super fancy "flame front" across the combustion chamber. It was because they are platinum tipped and were on sale for $1 less per plug. Do they work better than the Bosch platinums they replaced, no, but they worked just as well. I try to stick with the stuff that works for me. Marvel Mystery Oil, Seafoam, Kano Aero Kroil, Sta-Bil, etc. Sax, I do try new things on a regular basis but not because of outrageous advertisements or some Joe Blow on an internet forum swears he got a 35% horsepower boost by pouring it in. I'm still wanting to try Star Tron fuel treatment but can't find it locally. I agree with rdaystrom. Most of these gimmick products just mask or temporarily hide other problems. Just like running a thicker oil can most times hold down oil consumption in a worn engine just as well as well as some high dollar oil additive that basically just thickens the oil anyway.

Its running 'rich' (too much fuel being delivered to the combustion chamber) which is very bad for the engine. It dilutes the oil on the cylinder wall causing excessive wear. The float in the carburetor is probably stuck. Pick up the carb side of the mower and drop it from about 6" and see if it clears up. Use some kind of fuel system treatment like 'Seafoam' or 'Marvel Mystery Oil' to clean the system and keep the float free. Otherwise there may be a problem with the choking system, leaving the choke on all the time.

No one even mentioned the word compression and it makes me wonder about you people If the engine turns over without a plug in, it's because there is little resistance to turning over in a well oiled engine. With the plugs in the pistons now must generate compression of the air fuel mixture and this takes much more force. The power supply may be adequate to turn the engine over without plugs, but it may not be adequate to turn the engine over with plugs in. MAKE SURE you jump start CORRECTLY, with very good contact on terminals(you must have the right voltage which takes any contact, but right amperage as well which takes sufficient contact to pass that much currently in a given time which is why battery terminals are the size they are and not tiny wire connections) The engine should easily enough turn over with a breaker bar and socket on the crank pully if there is an easy way to verify this(only rotate it forward) if it takes a lot of resistance the engine is gummed up or starved for oil(or sludged) and good luck at this point.

I used to do the priming thing on older engines, but I forgot all about it. I drove 25 miles for a plug, but it didn't help me so I decided to take it in since the sooner it got in, the sooner (a week or two) it would get back. Before we took it off my truck, the mechanic gave it a yank and it fired up for him. It still wouldn't run off choke. Mechanic thought it was likely an air leak, but after spraying carb cleaner at gasket without effect, and finally realizing that this engine has a Nikki carburetor, he told me that they almost never have good results cleaning/rehabing them. So, I took it back home; gave it one more air and probe clearing; changed the apparently good fancy internal gasket; and still wasn't able to get it to start or fire. The mechanic was 20 years my junior, but I thought I was pulling almost as well, but no cigar. So I ordered up a new (hopefully the same) carb from Amazon. Then I read your post. I can see how middling compression might draw low fuel. I will see if I can find my tester and I will check the valves. But remember, until last weekend, and even two weeks ago, this engine always started easy for (apparently weak armed) me and ran fine for at least two hours.