Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Yo Jim

What you are fighting is simple physics here. The flyballs on the Polish School Engine probably weigh about 100 times what those tiny flyballs on the S-10 weigh, so your S-10's governor is lacking enough centripetal thrust to overcome the friction in the linkage, along with the governor spring compression modulus, which combined is likely only a small fraction less than the total friction of the Polish School Engine's linkage and return spring loading.

Lightening the spring compression on your governor would certainly help some, and break-in working (lapping as Gil suggests) of all the linkage joints to the best advantage will help gain some chance for your governor to do its job. But in reality, you are working against the "Scale Effect" that is so often encountered when either reducing or increasing the size of something that does work in a given size range, but may not in another scale.