It might seem I'm trying to "start" sumpin' with you Dell, ...but I'm not. I respect your knowledge immensely...
But you're mistaken about a couple things:
You wrote: "The reason for 400 rpms is so your centrifical ignition advance is RETARDED for eazier starting." Starting is from a STANDSTILL and the set idle speed of the engine is of no consequence at that moment. Further, the ignition advance is a function of distributor counterweights and spring tensions and have nothing to do with carburetion. Ignition advance is entirely dependent upon rpm....and for starting cares not whether or not, once running the idle speed will be in an rpm range calling for advanced timing. (And in any case, no significant advance occurs on these engines until 800-1200 rpm. The max advance does not occur until over 2000 rpm. As a comparison, typical automotive engines have starting timing around 10-degrees BTDC. The 9/2Ns have zero, while the later 8N's have 4-degrees BTDC. All N-engines have less than 10-degrees advance until approx. 1200 rpm. So, from the standpoint of starting ignition timing, an insistence on idle rpm of 400 is moot.)Later, you wrote: "That is why you have automatic ignition advance timing by the centrifical advance mechanism under your points plate. By restricting your governor to 1800 max rpms you actually reduce your governors ablility to handle engine power loads."
In actuality, the governor detects a lower-than-called for trottle-VS-rpm condition, and opens the carburetor throttle-plate wider whenever the underspeed condition is detected (and relaxes the carb throttle plate tensions when on-speed or overspeed is detected.) The fact that the maximum available speed is set for only 1800 rpm will not disadvantage the operation. If the throttle lever is at it's maximum deflection (normally calling for 1800 rpm) and the engine drops below that speed, then the governor will call for a more open carb throttle plate, and the engine will accelerate normally. The fact that no more than 1800 rpm is allowed by the governor will not diminish that action.
You are correct of course, that physically limiting the gov. action to only 1800 was unnecessary if the throttle lever movement had simply been manually limited by the operator. But the owner'sr decision to adjust his governor so as to limit his engine to a maximum of 1800 rpm in all cases does not reduce his governor's ability to act responsively at all. It merely causes the gov. to relax it's acceleration demands at any engine speed above 1800. In effect, it only resets the "overspeed" condition to 1800 rather than 2200. No loss of "governors ablility to handle engine power loads" or responsiveness occurs.
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