Re: mystery switch and mystery noise

Posted by HH56 On 2011/12/16 18:09:12

There is no vacuum connection on an Ultra. Kickdown is strictly controlled by the throttle rod adjustments so no switches either except for the neutral safety start switch operated by the selector shaft detent cam. It should drop out of direct drive below about ll mph or if below about 50 or so, when throttle pushed quickly open. Normally the vacuum section of fuel pump is in series between carb or intake manifold vacuum source and wiper. The extra vacuum connection could be for a windshield washer or a rear window wiper if you have (had) one. Anything else would be an aftermarket something. It is also possible the fuel pump vacuum is not plumbed properly if there is a tee but no accessories.

If you had an overdrive instead, the kickdown switch would be rectangular with 4 terminals. I suspect the item you mention is a spring loaded air check like device which slows the closing & prevents the accelerator from slamming shut and stalling the engine--sort of like the dashpot mounted at the carb on some of the earlier cars. IIRC it was a round cylinder about 1" diameter and a couple inches high with a plunger an inch or so long out one end.