CFLBob--95% of what I am doing is "Try it and see what happens" stuff. I know a fair bit from experience and from watching ten thousand videos, but it is mostly "Seat of the pants" engineering. My test today shows that the spring I am using is way to stiff---I needed to jack the rpm up to 800 before the governor would engage. So next thing was to try a few weaker springs from my spring collection. I came to the conclusion that not everything is "scaleable". Now I know why the full size Hercules engines ran the governor off a smaller diameter gear and it revolved much faster than my governor which is ran off the cam gear, which only rotates at 1/2 the crankshaft speed. It is much easier to get consistent, repeatable results from a faster turning governor and a much stronger spring than from a low speed governor and a weaker spring. Eventually I used the lightest spring I had and started reassembling things on my engine. I have two compression springs to deal with here---one inside the governor which I tested today and is difficult to access, and one which fits inside the lockout lever and is easy to access. Ergo, my best hit and miss action will be tuned by monkeying with the spring in the lockout lever. I don't think I have ever seen a model engine using this style of governor, and perhaps today I found out why. I'm not terribly concerned-if I absolutely have to, I will change the governor to the Farm Boy sliding sleeve on the crankshaft style. This is the style that all my other hit and miss engines use. If I do change the style of governor, 90% of the engine remains unchanged. I've only sold one set of plans, and if I change the governor style I will send the guy new updated prints of anything that changes.---Brian