Hercules Engine News

Including Economy, Arco, Jaeger & Thermoil


| March/April 1995



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 chang

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 screw.