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

I have changed out the governor springs on both my Vertical and Horizontal ET1/ETX engines. The ETX (M91) just pops along at a relatively slow RPM. When the ET1 (M90) fires, it hits hard and has a has a notable increase in RPM and coasting time compared to the ETX. Has anyone been able to slow this down? I thought I read something about removing a piston o-ring/machining down the top of the piston to lower the compression. I would note that the compression actually seems less by hand on the ET1 vs the ETX when starting. I would also note that I haven't been able to adjust the fuel properly on the ET1 to have it just fire one time as with my ETX. It double taps most of the time and while I am aware that would have an effect on the RPM it's firing so hard that if it didn't double tap it would still be spinning really fast.

I've also been considering what might happen if I adjust the timing.

I guess I shouldn't worry with it. With my full size engines, the goal was to have it coast for some time in between each time it fired, which this is technically doing. It is nice to see them turning over a bit slower though when they run.   

Unfortunately I don't have any RPM gauges to check it with. What I have I use on my steam engine and would require to much friction to get it spinning for this little engine.

I just got my ET1 last week and they are fun little models. As with my ETX it came with a rope starter but I have not needed it, as it seems to start right easily.