Have two of these & each one seems to have a different bore of the venturi (sprinkler). If anyone has one & can use number drills as pin gages, please tell me what the diameter of your Mark II venturi inlet.

Not a 'Piccolo' (0.8ccm), Not a 'Record' (1.5ccm), Not a 'Winner' (2.5ccm), Not a 'Bully' (3.5ccm)
it is a "Mach II" ..... a 2.5ccm diesel from the 1960's, back then it was "the" Team Race 'motoren' into the mid 1970's.

I have two of these, one has a venturi bore of (approx.) 2.4mm (or .098"), the second has a venturi bore of 3.16mm (or .129").

This seems to be quite a big difference, especially for a diesel. This difference appears far more then the difference between "stunt" and "racing"
It seems more like someone boreing out (drilling) until the motor becomes unable to to get a decent needle setting with proper compression settings. Or someone making a super-small intake to achieve "higher mileage" (read run to hot)

I just want to know which one was correct.