I'm trying to figure out if I have a failed governor on a Tecumseh/Sears
push mower engine.
The other day it failed due to what I think was dirty fuel, very likely
related to a similar generator problem I had recently. It started then
died and would not restart. Not even a sputter. And no gurgling sounds on
pushing the primer so something was clearly up with gas flow.
I drained the gas tank and flushed it out. I took the carb off--this is a
float valve / primer bulb /
non adjustable type and removed the float
chamber. I hooked up the tank, put a little gas in and played a bit with
the float, observing it allowing gas flow when down and stopping it when
up. Whatever dirt there was is probably gone by now and that was probably
all that was needed.
So I put it all back on the mower and it started up just fine. One problem
though: Overspeed and no reaction to the Idle/Run control lever.
Ah, I figure, I musta hooked something up wrong as it's been a long time
since I had one of those off. So I checked it. Can't find anything wrong
and there aren't all that many ways to hook it up: Lever from the back of
the control to short reach wire to spring to governor arm. Then long reach
wire from governor arm back to the throttle valve. I tried all sort of
things including weakening the spring but no dice. I can of course
throttle it by pushing on the throttle valve or governor lever but no sign
of normal operation. I even tried an identical carb I had on the shelf
from a long gone mower but no change.
The idea that the internal part of the governor would go bad at the same
moment there was some kind of carb/dirt issue doesn't seem very likely but
that's where I'm at now. I would like to prove that it does or doesn't
So besides looking for suggestions on what I might have hooked up wrong I'm
looking for a way to show if the internal governor mechanism is working or
Altering the load on the engine while being able to observe the governor
lever isn't too easy or safe on a lawn mower so with a normally running
engine one can prove governor operation by artificially choking the engine.
When the bad fuel/air mix causes the engine to slow you can see the
governor pushing the throttle wide open in an attept to maintain speed.
But that's no good here where the gov is already pushing the throttle too
So here's my idea: Disconnect all linkages and work the throttle valve by
hand. If I put a finger on the governor lever, pushing slightly to the
left (like the spring would) if I run the engine and rev the engine from
idle up to normal speed or a little beyond I should feel the governor lever
pulling to the right, as though trying to reduce throttle, yes? Better yet
keep fingers away and tie a mild rubber band on it. As I vary speed it the
lever should move back and forth and if it doesn't something internal is
wrong that I probably don't want to bother with. If it does work the way
it should then I know I've done something else wrong. Does that make