Breaker Plate stuck/Vacuum advance/Quick help please
- Thread starter GG-1
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Actually I am a hold out in regards to ignition in my area. Everyone has said "Go Electronic Ignition!!" "More power !" "More reliability!" BS,,,for my needs my old 440 does just fine on points.
No! And I don't have a vacuum gauge either. I used the suck method to check the canister.
But I suppose it's a good time to get a timing light, feeler gauges, etc, and learn.
I'm with you on that.. and I have 11" drums on all four corners that I love to operate and will never change out for discs.
That is fine and what I have done.
yikes.
First thing... Is the mechanical advance free? Can you turn the distributor rotor a little with your hand?
Second, you can't generate enough vacuum with your lungs to move the plate. I don't know the amount of negative pressure (vacuum) that you could make with your lungs, but to give you an idea, a young, healthy man might be able to generate 2 PSI positive pressure on a good day. More likely 1.5 PSI.. 2 PSI is equivalent to 4 inches of mercury.... 4"hg.
It takes 10"hg to move your vacuum advance 4 degrees. See where I'm going with this?? 10"hg is 4.9 PSI.
Third, the lack of vacuum advance won't cause this issue. Timing will... along with a bunch of other things.
Second, you can't generate enough vacuum with your lungs to move the plate. I don't know the amount of negative pressure (vacuum) that you could make with your lungs, but to give you an idea, a young, healthy man might be able to generate 2 PSI positive pressure on a good day. More likely 1.5 PSI.. 2 PSI is equivalent to 4 inches of mercury.... 4"hg.
It takes 10"hg to move your vacuum advance 4 degrees. See where I'm going with this?? 10"hg is 4.9 PSI.
Third, the lack of vacuum advance won't cause this issue. Timing will... along with a bunch of other things.
Thanks for the reply Big John, wish you had been around at start of the thread.. anyway..
First, How much is "a little" when turning the rotor? I wish I had known to check the mechanical advance last night.. will do it next week when I'm at the car again.
Second, I absolutely follow your logic/science regarding lung power, but still wonder how hundreds of youtubers demonstrate this feat (of making the plate move) so effortlessly by sucking the advance vacuum hose and also by simply moving the plate by the same degree with their fingers. I'm now confused.
With the vacuum advance canister still affixed to the plate and dizzy body, I was still unable to budge the plate a hair even using a screw driver with leverage. And I don't know if my "lungs" can pull the kind of vacuum you're talking about.
How would you suggest I test the vacuum advance canister now that I have it off and sitting at home.. mityvac?
Third, My power loss under load/throttle is right from 1 single rpm.. lagging, weak acceleration, then sadly just peters off at 30mph.. that's at a gradual rate/lower rpms... it's when I get on the throttle at all that it "puffs out" with soft popping as if there is zero acceleration, and just air suck. I was just reading a little about mechanical advance and that seems to make much more sense as a cause.. or part of the cause.
So check and set timing first?
OK, what do you suspect are the "bunch of other things"?
I'd like to approach the issue(s) in a logical, methodical order, as I learn, so I'm not just throwing time and parts at everything unnecessarily. Thanks.
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Also I remember some one here when I had problems finding a vacuum canister said they took a different canister from another dizzy and drilled a different hole location in the plate. The arm in this case went over the top of the plate not under. When I have a chance I will look up the thread of my topic on this .
So I can move the arm in & out on the canister now that it's out. There is a lot of resistance and it bounces back like there's a very strong spring pushing back from inside. I must use a great amount of force with the palm of my hand... normal?
However, a great amount of mouth vacuum on the nipple side of the canister does nothing to move the arm.
The video is not of me, nor is it my equipment.. but nonetheless it is apparently how it is supposed to function.
The video is not of me, nor is it my equipment.. but nonetheless it is apparently how it is supposed to function.
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I am going to take bad vacuum advance canister apart[the bad one in the pic] just to see it's guts. There is also a hex adjustment screw located inside the vacuum nipple. For kicks you could turn it one way or other. Maybe someone adjusted it so much it can't move with vacuum. My guess is the hex adjustment makes it more or less sensitive to vacuum and adjusts the preload on the spring /diaphram.
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Push it in manually and put your finger over the nipple. It should stay in. If it returns, the diaphragm is shot.
Note the distributor he's checking... VW 205T
Here's the vacuum specs from this page: The Old Volks Home - Distributor Parts & Specifications
Distributor: VW 113-905-205T, Bosch 0231 137 035 or 036
Advance/Retard Range: Vacuum (Advance Only): 17-19deg @ 1.3 In. Hg, 32-35deg @ 3.2 In. Hg
Full advance is 19 degrees at 1.3"hg.
1.3inches of mercury = .6 PSI.
It's comparing apples to oranges.
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