Posted by Clint Dixon (Curator of Antiquities) on Sunday, April 02, 2006 at 8:16PM :
In Reply to: ES71 expert needed posted by Steve Pellock on Sunday, April 02, 2006 at 6:59PM :
Hey Steve, your carb is exactly as it should be. Pressing on the gas pedal, or pulling the hand throttle out, never directly causes the throttle plate to open. Doing so only moves a physical "hard stop" out of the way so the main spring of the integral governor can do its job and open and regulate the throttle plate as designed.
This is exactly the reason that you should have a good functioning throttle return spring connected corectly between the throttle linkage and the fire wall of the cab. If this spring breaks, or if a set screw backs out as you mentioned, your engine will immediately be running at full throttle. In this case, full throttle would be at what ever the integral governor has been calibrated to allow the engine to rev to. Hopefully, you governor has not been tampered with and full throttle would be somewhere around 3000 to 3200 rpm. Not enough to hurt the engine but enough to suprise you while driving.
If you were to ever add a mechanical engine governor like those factory installed optional King Seeleys and Pierces that were available to control stationary engine use, you absolutly need a carburetor with an integral governor that functions as you described. These could be any of the following models: ET1, ET2, ET4, E7F1, and E7S1.
The way the manual shows the throttle return spring (14-23-2) hooked up is shown here. All of the trucks I have ever owned have had the throttle return spring clip (14-14-4)located further to the right, clear to the right side of the bell crank (14-14-1) between the cube shaped rotating end of the bell crank and the cotter pin shown through the end of the rod (14-14-3). Regardless of where this end of the throttle return spring connects, the other end must be secured to the fire wall in some manner. I now have mine secured to a bolt that comes through the floor pan from inside the cab but originally I had it connedted to the bracket assembly (14-11-20). Connecting the spring directly to the bracket works fine. Do not connect it directly to the shaft (14-11-1)unless it is to the inside of the bracket. If you connect the spring to the shaft where it bends down at the outside of the bracket you can press the gas pedal down far enough that the spring will slip off of the shaft and you will have to reach down and pull your gas pedal back by hand to slow the engine. I know. It happened to me a few times when stopping at crossroads until I figured out what I had done wrong.
Email me directly if you need more help.
Junior
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