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

And when the project fails it will be the engine’s fault, of course.

Out of the box my M17B started easily and ran reliably with a gasoline/Marvel fuel mix. Nothing has changed, it is a joy to run and has become my go-to demo engine. But it's a tiny engine and not suited to the labor of spinning a generator.

Although its crank is rigidly supported by bearings, neither end of the connecting rod is bushed. There is no lubrication system for the rod other than manual oiling when refueling. I suspect that the intended continuous running will eat the rod.

The M17B fires every compression stroke and it is not a slow revving engine, so it quickly heats and defeats the cooling capability of its water tank almost to the point of boiling. If not allowed to cool down when refueling, the heat will damage the o-ring.

Heavier flywheels and a more precise carburetor might slow it down a bit. Bushing the rod would allow maintenance instead of replacement but the minuscule wrist pin end probably won’t accept a bushing. The suggested cast iron ring might help if the cylinder material is hard enough to tolerate it.

In my opinion, a larger displacement, more robust hit-and-miss engine such as the M90/ET1 would be better suited to the project.