- Thanks Tbone and Captain. Interesting that "quiet" was one of the big selling points of Lawn Boy mowers... This is because they ran the exhaust straight down thru the mower deck into a larger round muffler... So not only did it have a good muffler, it was also muffled by the deck and the grass. Our GoKart conversion simply rotated the carburetor mounting to make the shaft horizontal... But this also rotated the exhaust port to the side. The original big muffler wouldn't fit because it wrapped around the shaft and didn't leave enough room for a clutch. The straight little muffler we ended up using actually worked pretty well... It was much more quiet than no muffler at all. I think I can fit a bigger one on it now.
- The original governor on these motors was interesting... And I think it played a role in keeping down the noise level. It basically was a wind vane connected to the throttle and sticking up into the cowling next to the fly wheel. The air flow from the fly wheel controlled it. So, when the mower came under more load, the wind from the flywheel would slow down, and the wind vane would open the throttle to apply more power. Pretty slick.
- Of course, we had no tolerance for any sort of "governor" when seeking to use this engine for a Go-Kart !
- I'm thinking I can use my laser RPM meter to find the right throttle setting to run the compressor at the specified 2300 rpm. Then just start it up and push the throttle to the mark.
More Back Story... This is actually the third or fourth Lawn Boy engine I converted for GoKarts back then. The first one came from the used mower and it even had electric start... Cost me $91. My son was able to just turn a key and start it up. One day, the engine was running exceptionally well. He was just screaming back and forth on the dirt road out front when... BANG! The engine blew up! He learned the importance of using mixed gas in 2-cycle engines from that. Father was not happy with him that day... He wrecked my beautiful little engine
- I told this to a friend at church and he said the local junk yard had three old Lawn Boys just sitting there. The junkyard sold them to me for $5 each so I was able to convert a couple of them... one for my son and one for the neighbor kid. Man, those kids got an education from those gokarts... They'd race back and forth and around the yard until until something broke. Then they'd have to haul their karts into the garage and weld or wrench on them to solve the problem.