MidwayKE70

4KC Electronic Distributor no vacuum advance

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Hi i have a ke70 with a 4kc and i have installed a electronic distributor and a Weber 45 DCOE. When i hook up my timing light i noticed i have no vacuum advance at all, when i increase or rev the motor the crank pulley mark goes towards 0° instead of advancing. Can anyone help me?

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Have you connected  a vacuum line from the inlet manifold to the distributor vacuum advance diaphragm?

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The vacuum actuator/bellows on these old distributors are known to have failed in the past. I came across one recently.  The quick check is to remove the distributor cap & rotor, so you can view the mechanism easily.  Remove the rubber hose from the carburetor base, or the inlet manifold in your case.

Put it in between your closed lips, & suck in.  You should be able to see the plate moving counter clockwise in the dizzy.  If it doesn't move at all, then problem is in the dizzy.  It could be the vacuum bellows itself, or maybe the mechanism of the stationary & moving plates are all "jammed" up.   Time to dissemble the dizzy & clean & oil it thoroughly. Once you have the bellows assembly out, you can test it by sucking, as it now doesn't have anything attached.

Let us know how you go.

Cheers Banjo  

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The fact it is electronic doesn’t change anything. It still relies on bob weights and vacuum advance to advance the timing

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How long ago did you purchase it off ebay, & how long has it been in service in your Rolla ?

Open it up, & all will be revealed.

Cheers Banjo

 

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So its been really flat to drive?  No sparkle at all??  I found that when I installed mine & set about fixing it.

You should pull the base plate out and look at the weights underneath, sometimes they are seized up from grease drying out. If they are not frozen, then it is just the advance curve that they programmed into the dizzy at the factory.

here's what I did-

https://www.rollaclub.com/board/topic/49927-how-to-fix-your-brand-new-ke-motorsport-electronic-distributor/?tab=comments#comment-511594

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Not quite the same as mine, but it works the same. Those weights should pivot outwards against the springs and they will turn the shaft a little as they do. That is what gives you igition advance, about 25deg.

Sometimes they freeze on their two shafts, as you can see in the photo. 

You can also see that fitting weaker springs lets the arms go out earlier and you get more advance faster. You could run the motor up to 3000rpm with a timing light on it and check the timing as it revs, then take off one spring and do it again. Let us know what happens..

The vac disphram you can activate by sucking hard on it. As the arm gets sucked inwards it pulls the baseplate of the sensor around & retards the timing.

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