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

Bonjour Jim,

I have also had more or less serious problems with all my Hit & Miss engines

Based on the assumption which is that your spark plug is correct and that gas arrives to the carburetor when clogged with your finger, I have had three problems :
1 - Trying to start in the wrong direction (!), no comment
2 - Bad timing, the spark did not occur a micro degree after the compression point, easy to hear so to fix
3 - bad carburation, 80 % of my problems

About the last point I use either Zippo gas (awfully expensive), Unleaded 98 or Alkylate.

Using also a drill when possible, I checked the plug (anode spacing <=1 mm), I had to find the opening degree which made it neither wet nor dry. It is really a question of a few degrees and it even changes when the engine becomes hotter.

Last point, on my vertical one, I also raised the tank to help the gas to go to the carburator.

Let us know how you progress, I am sure you will succeed especially because I never heard any complaint about Microcosm engines.