Hercules Engine News

By Staff

20601 Old State Road Haubstadt, Indiana, 47639

At shows that include gas engines, exhibitors often desire to
run engines at what might be called a slow idle. Most hit and miss
engines as originally set up do not have speed adjustment
provisions for 100 to 200 RPM speeds. 

On Hercules built engines, there are a number of slow down
changes that can be made. First, ignition timing needs to be

ed to a range of 3 or 4 degrees advance for each 100 RPM. For an
engine that almost stops before the next firing stroke, zero
degrees advance may be needed. Engines tuned as outlined often will
not speed up well nor produce much power under load.

On engines, properly tuned with the Webster or Wico ignition
system, timing can be quickly changed to zero advance by simply
setting the advance lever to the start position.

The spring in the governor spindle shaft may need to be changed
to a weaker one. If the governor spindle shaft is badly worn, it
may not be long enough to operate the detent at slow speeds. It may
have to be lengthened. On H and S model engines as well as older
models with the updated detent arm, the screw that touches the
governor  ignition can be turned in or replaced with a longer

On some engines there are one or more washers behind the
governor spring in the governor shaft. Removing these washers will
help to obtain slow down speeds.

The wedge on the bottom of the speed control lever can be built
up so the detent blade is moved closer to the detent block. This
way, it will engage at lower RPM.

On most gas engines, there is no compensation in the fuel mixer
for lower than normal air speeds through it. To compensate, it is
often necessary to close the choke to some degree so that enough
fuel is sucked in with the in coming air during the intake stroke
to provide a combustible mixture.

The information above is meant as a guide to obtaining slower
engine speeds. It often still involves some trial and error. If
parts relating to speed control are badly worn or poorly repaired,
speed adjustments may still be difficult.

In the next story, repairs and adjustments of the entire
governing mechanism will be covered.

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