carsandcameras is a fun to watch.. but bad example to follow for the most part..
unfortunately they show some very bad practive while it runs and deliberately hide how miserably it fails in short order...
But alright..
there are two 212 tillotson engines.. the E and the R..
the E is for all I know NOT raceprepped.. to me that means it's governor is still installed and
there are little to no mods installed.
(it comes with a limited 1year warranty for non racing applications)
then there's the 212 R which for all I know is essentially exactly as prepepd as the Tillotson 196R (just not a true 196cc but a 212cc clone)
the governor is removed, cam and springs are installed (hopefully a billet con rod)
and a billet flywheel (the 196R turns ~8k)
NOW.. governed to 5500 rpm is not a thing really..
there are rpm limiting ignition coils
but frankly I doubt it's installed on any of those engines. (people tend to avoid those in general)
Then there's the "makeshift rpm limiter" namely valve flutter, that usually ocurs right around 5000-5500 rpm when NO heavier valve springs are installed and the actual governor is removed
Chances are, that's what CAC meant by saying it's governed at 5500 rpm.
I can't tell for sure, whats certainly NOT the case it that there is an actual governor
(governors !== rpm limiters)
that's governing the engine to 5500 rpms..
it's not impossible that they got hold of a rpm limiting ignition coil and miscalled it "governing"
when they meant "limiting"..
but most likely they talk valve flutter (which again is just limiting not governing)
One would need to open up their engine to know for sure
'sid