ggoyeneche, you got me in the right ballpark - it was M10 X 1.25. Important thing was realizing it was metric not SAE. Sorry, didn't get a moment to log back in and thank you last week.

Usually, small engines used on lawnmowers are prevented from overspeed by an wind vane, or a sail, that is located adjacent to a spinning fan. The fan will be attached to the crankshaft, so the faster the crankshaft turns, the faster the wind blows. The vane has to be free to move, and it has to be attached to the throttle arm somehow, so that the throttle is closing, as the rpm's increase. There is always a cover or shield over the fan, and this cover will have to be removed before you can inspect the mechanism.

I finally got around to working on this mower again and took the carb off and cleaned everything out with carb cleaner and blew compressed air through all of the jets and orifices and made sure everything was clear. I put it back together and ran it with the blade disengaged and it ran great for about 30 seconds. Then it idled down for a second before speeding up uncontrollably to the point that it sounded like it was gonna blow up. I quickly reduced the throttle and engaged the blade to slow the engine down. Then I went to test it out and like before, after running for a little bit with a load on the engine, it dies. It will run as long as you want with the blade engaged and stationary, but if you try to mow with it it dies after only about 30 seconds of mowing. I also noticed that when the blade is engaged the engine speed is fine, but if you disengage the blade, it revs way up. I noticed that if I turn it off when the engine starts to rev way up, then restart it right away, it will run fine again for about 30 seconds, then rev way up again. I can repeat as many times as I want. As long as I turn it off, it will run fine upon restart, even if I do it right away. Any ideas? This post was edited by jjw2112 on Sat, May 31, 14 at 21:15

Don't take this the wrong way, but I do think you are being too picky and anal retentive about the Suzuki. Starting on three pulls is fine by me, and I have owned more than a dozen Suzuki's, including about half which were Commercial Prolines such as the 22040 and 22043. Yours is an early Consumer model and probably only has a choke. Later models also had a primer button because the Mikuni carb often wouldn't flow enough fuel when cold. However, if you're starting with three pulls, you got no complaints. Also, You are not doing your engine any favors by running 32:1. Toro and Suzuki have recommended 50:1 since day one (mid 1980's) and oils were not as good 30 years ago. They also approved TCW-3 oils. Before you or other readers go nuts about the TCW-3 recommendation, keep in mind that this is a relatively low revving 2 stroke. It's governed at 3600 rpm and has a max speed of 3900 or 4000 rpm. This is not a high end string trimmer turning 10,000 rpm or a chain saw doing 12,000 rpm. Suzuki knew what they were doing. Lastly, I disagree with the previous poster about premium fuel. Usually I find him well informed and on point, but not in this case. Premium doesn't run "hotter" or "cooler", just has less tendency to knock and preignite, Main potential advantage to premium is that it is sometimes available without the 10% ethanol. And ethanol is bad news for the rubbers and elastomers in the carburator. Ethanol is also hygroscopic (attracts water) and the resulting moisture will attack aluminum and zamak carburetor parts. If the premium has ethanol, it's then no better or worse than regular gasoline. My recommendation would be to run ethanol free gas where possible, stay with recommended 50:1 oil premix, and use a high quality oil. A synthetic is great, but really not needed. As for Marvel oil. It won't hurt anything, but I'm not as sold on it as some people. If you start having a lot of trouble starting (8 to 10 pulls), then it may be time to look at the crankshaft seals. These are relatively cheap ($7 to $10) each, but a major job to fully disassemble and replace. BTW, if you want the Toro/Suzuki manual (492-0260), send me an email, and I'll bounce back with a PDF.