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

Hi Raphael, ..I only have a good running, sorted-out M90 engine & sorry you're having new engine running problems,
 as multiple issues could exist .Your engine running videos are very interesting & i Didn't notice any excessive dark exhaust smoke which would indicate an over rich fuel condition, so maybe it's too lean...How did you fix the initial  "no compression" symptoms ? assuming you now have good "snappy" flywheel compression flip feel & good, normal carb intake suction since any basic engine issues including intermittent ignition cut-out problems could make carburator tuning
a nightmare. I keep an intentional small sparkplug wire connection arc gap visible to instantly monitor ignition issues during engine running problems... As your M12 carburator is probably a lot more complex than the previous M90 engine series simple fuel mixer needle valve,  Does your instruction manual include clear step by step tuning proceedure illustrations, sometimes using a tachometer & fuel line "pinch" tests to help you achieve organized,  high speed, low speed, stumble free rpm transition & idle speed stops tuning adjustments ?   Hope you get all sorted out & share with us...Regards,...tom.