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I have a question regarding old Briggs model 23A and 23D ignitions.


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#1 classic ONLINE  

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Posted January 02, 2016 - 11:48 AM

The Briggs 23DFB uses the 3 leg armature and flywheel magnets to create spark. Also, the 23DFB uses a points plunger that is actuated by a flat the camshaft. The 23AFB uses the Magnamatic armature assembly which consists of a coil mounted behind the flywheel, and the magnets are on a small hub that is mounted to the crankshaft. The flywheel on the 23AFB has no magnets. Also, the points on the 23AFB are actuated by a lever that contacts the spark advance weight on the camshaft gear. The question I have is, can the flywheel and Magnamatic coil assembly be used on a 23DFB engine together with the points plunger points system of the 23DFB? I know that the parts from the 23AFB will mount up to the 23DFB and the key slots on the crankshafts are in the same locations.
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#2 DougT ONLINE  

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Posted January 02, 2016 - 03:41 PM

I'm not sure on the answer to your question but I did upload the service manual for these engines here.  http://gardentractor...30pt-1-and-pt2/

I would think it would work as long as the magnets are passing the coil legs when the points open. Looks like there are different styles of magnet armatures on the magnamatic ignition. I don't remember them having flywheel keys. Most of my experience on these engines are just the plain 14 and 23 without the suffixes.


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#3 classic ONLINE  

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Posted January 02, 2016 - 05:44 PM

Thanks Doug, I appreciate it. I have a Briggs parts list book and I've been going over some of the differences with the 23 series engines. There are two different types of crankshaft rotors. The early style has a threaded pin that retains the rotor, and the later style has a clamp to retain the rotor. It's about the only difference I can see between these engines other than the crankshaft part numbers. The later rotor has separate timing marks for the 23 and 23A, also. I'm thinking these early Magnamatic armature assemblies and rotors should work with the later points plunger set up. The keyway in the crank that I'm referring to is the keyway for the rotor. The 23 and 23A do not have flywheel keyways as you mentioned. I was just wondering if anyone here has done it before.

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Edited by classic, January 02, 2016 - 05:51 PM.


#4 classic ONLINE  

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Posted January 02, 2016 - 06:02 PM

Doug, what I'm looking to do is to use a 23DFB block, cam, and points plunger assembly along with the crankshaft and Magnamatic coil/armature assembly from a 23AFB. The 23AFB crankshaft for the 23AFB does not have the notch for the tab for timing the 23DFB flywheel. I suppose I could make the notch in the 23AFB crankshaft, but it would have to be in the exact location in order to use the 23DFB flywheel and 3 leg armature/coil assembly.

Edited by classic, January 02, 2016 - 06:12 PM.


#5 DougT ONLINE  

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Posted January 03, 2016 - 05:30 PM

Doug, what I'm looking to do is to use a 23DFB block, cam, and points plunger assembly along with the crankshaft and Magnamatic coil/armature assembly from a 23AFB. The 23AFB crankshaft for the 23AFB does not have the notch for the tab for timing the 23DFB flywheel. I suppose I could make the notch in the 23AFB crankshaft, but it would have to be in the exact location in order to use the 23DFB flywheel and 3 leg armature/coil assembly.

I would think you could get away with that. The spark would have to happen about the same place on both engines. I thought you were talking putting the magnamatic system on the D shaft.


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#6 classic ONLINE  

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Posted January 03, 2016 - 09:36 PM

Thanks again Doug. It does seem like the combo should work. I'll have to decide on what route to go when I get to it.




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