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.

I have a problem just like this one my toro was running pretty good only thing was you had to pump it everytime u started it even if you just shut it off for a second after running it for 30mins my partner decided to clean the ball out now the pump leaks when u pump it and for a day we were pouring gas in the carb to get it started now after we do that it just stalls out im not sure what he did and either is he i wish he would have left it alone the season is almost over this isnt my post so if anyone has any advice for me please email me at gballer823@gmail.com i am going to try and get it fixed myseld tomorrow afternoon thank you. Greg

Is that a 10684? Use the fuel stabilizer all the time - put it in your gas can when you get gas. I think one of the valves is sticking a little. I would use a gas and oil additive such as Seafoam or Marvel Mystery Oil. Certainly won't hurt anything and will free the valve stems and generally clean the engine and fuel system. Also, how long has the air filter been on it?

'however the head, top of the piston, the top of the block and the valves are all fairly heavily coated with carbon - worse than I would imagine even for a 10 yr old machine (although I wouldn't consider myself any kind of any expert!).' Possibly from using stale gas. I tangled with one of these recently and didn't clean anything - just put in an E3 plug and fresh oil and gas (my 4-cycle 'mix' containing MMO+Sta-bil). The thing started right up and runs like a new one. Get this - the guy had put back 25 gallons of gas in 1999 for Y2K, and was trying to use it up in the mower in 2005! He passed away and I had nothing to do with it, honest! I expect continued use of fresh fuel with my mix by his comely widow will eventually clean it up, but I have to go over there and check on it FREQUENTLY. By all means do not scrape anything in the engine. Be very careful removing the old gasket remains. You'll probably have some more surprises when it does start, like a gummed-up carb or worn rings, but you might get lucky, too. Change the oil and use SAE 30HD in it - Castrol, Quaker State, etc.