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CB750 points plates Toyo, Hitachi, Nippon Denso, Futaba

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HondaMan:

--- Quote from: 69cb750 on September 23, 2024, 04:35:51 PM ---
--- Quote ---In my experience, the Hitachi points and condensors last the longest. Their points have curved contact faces while the others were largely flat.
--- End quote ---
I have brought ten bikes back to life with original points plate.
Most recent bike refused to start, tried two spare point plates, refused to start.
Had to use plate from running bike, quite the surprise, Japan condensers only last 55 years then they quit.

--- End quote ---

The old condensors were made with paper and a waxy substance as their insulator (they called it a 'polymer', but I am dubious of that...). This insulation material dries out when it sits for a long time unused. To 'bring it back' often requires a usage of some sort: I usually apply an AC voltage to them (if they are not shorted from some failure) and leave it 'ON' for about 24-48 hours (some went weeks when I forgot about them). They were designed to redistribute the insulation after being parked for a long time (as many bikes are) with some use: this has typically been a good way to do it.

I have a couple of old model train transformers that supply 12vDC to a rheostat from a 16 volt AC transformer: both voltages are available on the unit. 'Tis a handy thing for this process. ;)

69cb750:

--- Quote ---I have a couple of old model train transformers that supply 12vDC to a rheostat from a 16 volt AC transformer: both voltages are available on the unit. 'Tis a handy thing for this process. ;)
--- End quote ---
How many have you revived ?
What is the success/failure rate ?
12v dc or 12v ac ?

HondaMan:

--- Quote from: 69cb750 on September 24, 2024, 12:19:41 PM ---
--- Quote ---I have a couple of old model train transformers that supply 12vDC to a rheostat from a 16 volt AC transformer: both voltages are available on the unit. 'Tis a handy thing for this process. ;)
--- End quote ---
How many have you revived ?
What is the success/failure rate ?
12v dc or 12v ac ?


--- End quote ---

I 'saved' almost all of them, except some that had dents in their cases: they ended up having low-grade shorts in them.
In the little toy-train transformer I use, there is a 16vAC transformer and a rectifier (full wave) that wires up to the throttle knob for the DC output part. I use the AC output (provided for other train accessories, like lights and sounds, etc.) with a resistor

This all reminds me: I have to dig that gizmo out and 'wake up' some of the old Japanese Daiichi condensors I found last week in an old box: they are probably 20 years old and still brand new.

CycleRanger:
Here's a crusty ND plate with ND points with those funky condensers that have the blobs of glue. I assume it's for a 350F based on the 333 marking?
I got this with several 750 plates from ebay years ago.

jwurbel:
For what’s worth, I ordered a set that came up on EBay simply because the price, $48 plus free shipping, was so low.  The set is clearly stamped FEW.  Not sure of the state of the condensers.  Mark, how do you charge them? 

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