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I've read a couple of times Ray's strong cautionary note about getting the MPS outer plug back in exactly the same spot it was before removal for mixture adjustments. What variable does the outer plug govern?

hy,, btectonic,, i have a good suggestion for you ,, for to make sure 100%,, you go on the ,,,brain box ,,,or cpu,, and you look the wire color for the no, 7 ( example ,,) and afther you go to see the plug on the mps ,, and you look on what side is the no,7 ,, example if the no, 7 wire on the brain box is ,,yellow,, on the ,,mps,, plug the no.7 is yello,, albert

btectonic, please look foor the "outer screw" header at Paul B Anders excellent site:
http://members.rennlist.com/pbanders/ma ... djustments


Lars S

The outer plug governs how far out the copper diaphram flexes. Since the movement of that diaphram is additive to the existing spring pressure exerted against the aneroid chambers inside....it allows a change or"rate" or speed with which the aneroid chambers expand when you open the throttle. Because teh copper plate is thin and flexible and very large in area....and being acted upon by both extrenal atmospheric pressure and vacuum inside....it reacts very quickly.

When the copper diaphram is vacuumed in...it adds spring pressure to that from the aneroid cans to move the armature into the coils ...say...X far. When you step on the throttle...and vacuum is dumped....the copper diaphram flexes very quickly outward. Though the aneroid cans still govern how FAR....in general...the armature moves out of the coils....the quick release of the extra pressure by the copper diaphram....allows a quicker response ....and slightly further movement of the armature...hence...quicker and higher full load enrichment.


The outer plug is the adjustment stop for the movement of the full load enrichment copper plate. If you screw it too far out...you get hideous bog down spots off the line. Too far in...and you get lean flat spots and misfiring. Ray