I've got a feeling the governed full speed RPM of the 6 HP Tecumseh "Snow King" engine on my 1964 Ariens Sno-Thro has been decreasing over the years, as the "Widow Maker"* doesn't seem to be launching snow as far as I remember it could a while back, and nothing seems obstructed or noticably worn. ('Course I can't toss snow as far as I could back in '64, but there's not much I can do about that. )
I've got a spark induction tach, but when I looked in the original manuals this morning, there's no mention of what the full speed RPMs should be set to.
The governor spring has probably taken a set over the years, probably because of my habit of shutting it down by leaving the engine running at full speed and closing the fuel petcock, which leaves the spring stretched a bit all the time.
Thanks guys and Happy New Year,
- So named by me because it predates the safety features on today's snow blowers. The front halves of the auger ends are exposed and ready to grab any pant leg in range and there's no dead man system, other than waiting for the gas tank to run dry.