Why do I get myself talked into these things? ;-)
Bit of a long shot that someone else has one of these, but I've got an
old 10" tiller with a Tecumseh TC200 2102C engine on the bench (the
tiller says 'Dynamark' in one spot, and "Noma" in another, so I'm not
sure who the manufacturer is; Google returns basically nothing for
The machine idles OK, but was struggling under load. I noticed that the
throttle plate wasn't opening all the way - if I held it open manually,
the engine would run at a healthy rate.
The carb on this thing is a tiny Tillotson HU. The engine has a vane
governor, and a spring connecting the throttle cable to the governor
mechanism. I'm reasonably confident that this spring has gone weak or
stretched (the throttle plate itself can be moved perfectly by hand
without resistance), explaining why the throttle plate doesn't open all
the way when the throttle is squeezed.
However, there's no separate spring for returning the throttle plate
closed when the throttle is released; I'm wondering if there should be,
and it's gone missing over the years - or is the governor vane supposed
to also close the plate all by itself when it's not fighting against the
tension of the spring at the end of the throttle cable?
(I can hunt around for a replacement spring, or even - ugh - hack things
by shortening the existing one, but it'd be nice to know whether I'm also
missing a return spring on the carb side of things)