RickB wrote:
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ralphyost wrote:If you cant get 2650 under NO LOAD then you will never get to 2500 under load (or Wide Open Throttle WOT).
Not necessarily so.
2650 rpm is "high idle" or the maximum rpm setting. It is determined by the position of the governor flyballs and beyond that speed the "speed stop" prevents more fuel from entering the injector pump.
2500 rpm is the rpm at which
maximum rated horsepower is produced. If the boat is fitted with a "well matched" propeller it is also the rpm at which the "fuel*stop"*prevents further*travel of the fuel control rod and no additional fuel*can be*delivered to the injectors.
These are three separate and adjustable settings. Max rpm can be obtained in neutral with very little fuel, that setpoint is called "high idle."
Maximum*power available *is controlled*by limiting the
maximum amount of fuel that can be delivered, that setpoint is called the "fuel stop." It used to be called the "smoke stop" because any fuel beyond that amount will only cause black smoke and engine damage from overheating.
Idle is set by limiting the
minimum amount of fuel that can be injected.
-- Edited by RickB on Tuesday 1st of March 2011 02:09:59 PM
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Rick
Good explanation...... and a much more precise explanation.
However, I still dont get it when you say "not necessarily" to my statement that if the engine cannot achieve 2650 RPM (when the fuel injector pump is at the speed stop), then it will never be able to deliver the max RPM at full load.
If the speed stop is incorrectly set, and reduces the max RPM (NO LOAD), then the throttle travel on the fuel injector pump is not moving far enough to allow the correct amount of fuel to the injector system.
If the injector pump is not allowed to provide the correct MAX amount of fuel (based upon throttle travel), then how will the boat ever be able to produce the max power available to get to MAX RPM UNDER LOAD ?
???
thanks
R,
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