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New carb and dist?

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66CTBronco

66CTBronco

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Nov 18, 2020
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it's a kit. fits all autolite 1100's. i bought some other things like hardware that i ended up not using and some 1/2" welch plugs that actually came with the hardware kit... only needed one. the carb was really dirty ended up using napa solvent for a while and vinegar for a while in my ultrasound for days and days to clean it all then an entire can of gumout carb cleaner inside the ports etc. i tore apart the power valve which the website and many autolite 1100 sites said dont do, even the autolite manual said not to tear it apart but it was plugged solid so what did i have to lose. anyway runs like an absolute champ so much more power now that i have the right carb to go with the distributor. Mike's got a great website lots of help and articles and parts galore. I ended up getting two rebuild kits, one hardware kit, and a bag of welch plugs...
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1970 Palmer

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Mar 2, 2020
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455
The "power valve" in a 2100/4100 Autolite carb controls the fuel mixture and enrichens it at a low manifold vacuum, such as at full throttle.

The "valve" your referring to looks like a Autolite 2100/4100 Power Valve but is not the same thing, which is why they don't call it a "power valve" on the Autolite 1100 carbs. It's a "spark valve" and controls the amount of vacuum being sent to the distributor advance diaphragm. Basically it controls your ignition timing. It's why this model carb needs to be used in tandem with a matching distributor.

Both kinds of valves are operated by manifold or Venturi vacuum are very sensitive to the valve diaphragm spring pressure. It would be very difficult to take one apart and then reset the exact inches of vacuum that they were originally adjusted at the factory. You would require some special vacuum measuring equipment. This is why most people just pull their power valves, look for the marking stamped in the edge and "adjust by replacing the valves" with a new one with their desired adjustment. I'm not aware of a choice in Spark Valves for the 1100 Autolite carbs, but maybe they did make a "high altitude" valve, which would have been adjusted to a lower vacuum setting?
 
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66CTBronco

66CTBronco

Contributor
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Joined
Nov 18, 2020
Messages
89
Loc.
New england
No, i did not mean the spark control valve. I picked up this carburetor because i have a load-o-matic distributor and the existing carb was incorrect. The power valve assembly is internal, has a brass piston covered by a 1/2" welch plug on the top of the carb, has a few phenolic spacers, a tapered coil spring and an angled rod that holds in place a single check ball and a very tiny spring. I replaced the spark control valve with a new one, and since i could not locate parts for the power valve, including the main well tube which i believe is a press fit and can't be removed easily, i had to disassemble it in order to clean it. a 1/16" drift punch on the back side of the piston and a few gentle taps with a plastic hammer pressed out the rod. the spring and check ball were held firmly in place with very thick varnish. It is this valve to which I was referring above.
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Ovalis

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Was your power valve froze up? I've had good luck freeing them up soaking them & ultrasonic cleaning and got them going again. I never opened one up before.
 
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66CTBronco

66CTBronco

Contributor
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Joined
Nov 18, 2020
Messages
89
Loc.
New england
it was frozen solid. there was varnish around the brass piston, and i have no idea what was inside where the check ball and spring were. not seeing any drawings of what was below the bend end of the rod i had to prod carefully. the rod was stuck in the hole there was gunk around the spring and the piston was held fast with more varnish. When i pressed out the rod from the piston i was able to press the piston out of its hole, obviously removing the aluminum welch plug first, then had to poke carefully with a straight pin in the hole till i found the ball, it came out then poked more gingerly as i felt something but as of yet could not ascertain what it was, i was able to clean around the outside edge of the channel and center so i figured there was a tube or something in there, turns out it was this tiny spring about 1/2" long and probably 1/16" diameter. glad i was gentle with it. after that different size carb brushes and poking and prodding with the nozzle from the carb cleaner can. I had this in napa cleaner in a 200 watt ultrasonic cleaner for probably 4 hours, soaking overnight and during the day when i wasn't in the shop over the course of a week or so, couldn't budge the stuff. then i tried vinegar and as looking at other youtube cleaning solutions. the heat and ultrasound did a good job but the last bit of stuck varnish came off with hot vinegar in the ultrasonic tank. all holes i had to poke something through, wire, gauges, brushes, etc... toughest carb i've ever had to rebuild!!
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1970 Palmer

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Mar 2, 2020
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455
Glad that you stayed with it and figured it out. You can bet that a store-bought rebuilt carb would not have received the same amount of work.
 
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66CTBronco

66CTBronco

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Joined
Nov 18, 2020
Messages
89
Loc.
New england
i'm sure of that, thanks Palmer. I'm an ana1-retentive engineer on the verge of being an enginerd... i was still curious/nervous that i hadn't cleaned it thoroughly enough, and kept looking at videos and reading to find out if there was yet a better way to clean things. I still have half a gallon of the old Gunk Hydroseal which was nasty stuff but boy did it clean carburetors! i'll probably run a couple bottles of Techron through the tank to keep cleaning the system and carb, hopefully not to loosen any gunk upstream that could plug my recent work. I was surprised at the lack of information out there on the power valve, even Mike's carburetor said he rarely takes them apart but his video on power valves doesn't show how to take it apart. If there's a place to create writeup's and how-to's i may do that and submit it to the authorities on this forum.
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