After carelessness, meddling with an engine comes next in the list of
bad habits. The tinkering engineer never knows whether his engine is in
good shape or not, and the chances are that if he should get it in good
shape he would not know enough to let it alone. If anything does
actually get wrong with your engine, do not be afraid to take hold of
it, for something must be done, and you are the one to do it, but before
you do anything be certain that you know what is wrong. For instance,
should the valve become disarranged on the valve stem or in any other
way, do not try to remedy the trouble by changing the eccentric, or if
the eccentric slips do not go to the valve to mend the trouble. I am
well aware that among young engineers the impression prevails that a
valve is a wonderful piece of mechanism liable to kick out of place and
play smash generally. Now let me tell you right here that a valve (I
mean the ordinary slide valve, such as is used on traction and portable
engines), is one of the simplest parts of an engine, and you are not to
lose any sleep about it, so be patient until I am ready to introduce you
to this part of your work. You have a perfect right to know what is
wrong with the engine. The trouble may not be so serious and it is
evident to you that the engine is not running just as nicely as it
should. Now, if your engine runs irregularly, that is if it runs up to
a higher speed than you want, and then runs down, you are likely to say
at once, "Oh I know what the trouble is, it is the governor." Well,
suppose it is, what are you going to do about it, are you going to shut
down at once and go to tinkering with it? No, don't do that, stay close
to the throttle valve and watch the governor closely. Keep your eye on
the governor stem, and when the engine starts off on one of its high
speed tilts, you will see the stem go down through the stuffing box and
then stop and stick in one place until the engine slows down below its
regular speed, and it then lets loose and goes up quickly and your
engine lopes off again. You have now located the trouble. It is in the
stuffing box around the little brass rod or governor stem. The packing
has become dry and by loosening it up and applying oil you may remedy
the trouble until such time as you can repack it with fresh packing.
Candle wick is as good for this purpose as anything you can use.
But if the governor does not act as I have described and the stem seems
to be perfectly free and easy in the box, and the governor still acts
queerly, starting off and running fast for a few seconds, and then
suddenly concluding to take it easy and away goes the engine again, see
if the governor belt is all right, and if it is, it would be well for
you to stop and see if a wheel is not loose. It might be either the
little belt wheel or one of the little cog wheels. If you find these
are all right, examine the spool on the crank shaft from which the
governor is run and you will probably find it loose. If the engine has
been run for any length of time, you will always find the trouble in one
of these places, but if it is a new one the governor valve might fit a
little tight in the valve chamber and you may have to take it out and
use a little emery paper to take off the rough projections on the valve.
Never use a file on this valve if you can get emery paper, and I would
advise you to always have some of it with you. It will often come
handy. Now if the engine should start off at a lively gait and continue
to run still faster, you must stop at once. The trouble this time is
surely in the governor. If the belt is all right, examine the jam nuts
on the top of the governor valve stem. You will probably find that these
nuts have worked loose and the rod is working up, which will increase
the speed of the engine. If these are all right, you will find that
either a pulley or a little cog wheel is loose. A quick eye will locate
the trouble before you have time to stop. If the belt is loose, the
governor will lag while the engine will run away. If the wheel is
loose, the governor will most likely stop and the engine will go on a
tear. If the jam nut has worked loose, the governor will run as usual,
except that it will increase its speed as the speed of the engine is
increased. Now any of these little things may happen and are likely to.
None of them are serious, provided you take my advice, and remain near
the engine. Now if you are thirty or forty feet away from the engine
and the governor belt slips, or gets unlaced, or the pulley gets off,
about the first thing the engine would do would be to jump out of the
belt and by the time you get to it, it will be having a mighty lively
time all alone. This might happen once and do no harm, and it might
happen again and do a great deal of damage, and you are being paid to
run the engine and you must stay by it. The governor is not a difficult
thing to handle, but it requires your attention.
Now if I should drop the governor, you might say that I had not given
you any instructions about how to regulate it to speed. I really do not
know whether it is worth while to say much about it, for governors are
of different designs and are necessarily differently arranged for
regulating, but to help young learners I will take the Waters governors
which I think the most generally used on threshing and farm engines.
You will find on the upper end of the valve or governor stem two little
brass nuts. The upper one is a thumb nut and is made fast to the stem.
The second nut is a loose jam nut. To increase the speed of the engine
loosen this jam nut and take hold of the thumb nut and turn it back
slowly, watching the motion of your engine all the while. When you have
obtained the speed you require, run the thumb nut down as tight as you
can with your fingers. Never use a wrench on these nuts. To slow or
slacken the speed, loosen the jam nut as before, except that you must
run it up a few turns, then taking hold of the thumb nut, turn down
slowly until you have the speed required, when you again set the thumb
nut secure. In regulating the speed, be careful not to press down on
the stem when turning, as this will make the engine run a little slower
than it will after the pressure of your hand is removed.
If at any time your engine refuses to start with an open throttle,
notice your governor stem, and you will find that it has been screwed
down as far as it will go. This frequently happens with a new engine,
the stem having been screwed down for its protection in transportation.
In traveling through timber with an engine, be very careful not to let
any over-hanging limbs come in contact with the governor.
Now I think what I have said regarding this particular governor will
enable you to handle any one you may come in contact with, as they are
all very much alike in these respects. It is not my intention to take
time and space to describe a governor in detail. If you will follow the
instructions I have given you the governor will attend to the rest.