----[Please read http://ercoupers.com/disclaimer.htm before following any advice in this forum.]----At 12:06 PM 2/28/2005, you wrote:
Do any of you know what the reason is that the timing on a C-75- or C-85-12 is set
RIGHT MAG --28 DEGREES BEFORE TOP DEAD CENTER, AND the LEFT MAG -- 30 DEGREES BEFORE TOP DEAD CENTER ? ??
Short answer; to get an even mag drop.
Longer answer: the Left mag fires the Lower plugs which are closer to the exhaust ports where the mixture is Leaner. Leaner mixture burns slower so it has to be ignited earlier, i.e. more before TDC.
Why, you may say, don't more engine types use staggered timing? Most engines fire the lower plugs on one bank and the upper plugs on the other bank from each mag, so there is no imbalance between the mags, so the mag drop is even.
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