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Allan G, NickL
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Original Post (Thread Starter)
#839641 02/10/2021 6:46 PM
by Stasch
In process of restoring 67 Lightning. Would like some feedback on the merits of keeping the original rectifier and zener diode. Is there a way to test the units I have to see if they are functioning properly? Or should I buy new? If buying new, which ones are the best? Also, what is a tympanium electric voltage regulator? Is that a replacement option? Thanks.
Liked Replies
#839653 Feb 10th a 08:38 PM
by Stuart
Originally Posted by Stasch
Would like some feedback on the merits of keeping the original rectifier and zener diode.
If they work, you won't have to spend on replacements. smile

Originally Posted by Stasch
way to test the units I have to see if they are functioning properly?
Connect the electrics. Connect the rectifier and Zener last. Connect the rectifier before the Zener.

When connecting the rectifier, connect the Brown/White(?) wire to the centre plate last; if the fuse blows, replace both rectifier and Zener with a combined regulator/rectifier (see below).

When connecting the Zener, connect the Brown/White(?) wire to the male spade terminal last; if the fuse blows, replace both rectifier and Zener with a combined regulator/rectifier.

When you can run the engine, connect a Voltmeter (or multimeter set to Volts) across the battery; good fully-charged battery, meter should display 12.6V.

Start the engine and raise the engine rpm slowly while watching the meter, it should display Volts increasing with rpm until about 3,500~4,000 rpm, when the meter should display between 13.8V and 15.3V. Continue to increase the engine rpm until you are sure the meter displays the same Volts despite the increased engine rpm. The meter should not display reducing Volts until the engine rpm is allowed to fall below the aforementioned 3,500~4,000 rpm.

Originally Posted by Stasch
should I buy new?
Ime, no. Apart from the expense (~$30 each?), some new Zeners are unreliable - allowing DC Volts well in excess of 15V (19V? eek ). Regrettably, you can't tell if a Zener is faulty 'til you connect it and test it as above, but then some vendors refuse to exchange or refund. frown

Originally Posted by Stasch
what is a tympanium electric voltage regulator?
Tympanium is one make of a number of different combined electronic regulator/rectifiers; even Wassell Lucas offer them.

If you buy a reg./rec., I advise one of only two:-

. either plus;

. or Podtronics 3-phase;

... Podtronics is about three times the price of the Ebay one, but has US-based backup if you need it ...

. the Pod definitely doesn't require spark plugs, caps or HT leads to be changed for resistive; the Ebay reg./rec. only might; some other reg,/rec. definitely do.

Reasons I advise only 3-phase reg./rec. are:-

. You can connect your bike's existing single-phase stator wires to two of of the reg./rec.'s three Yellow wires, either detaching the unused third Honda Yellow wire from the plug or insulating the end of the Pod's unused third Yellow wire.

. If you wish/have to change your bike's stator, new ones are all about the same price irrespective of output, which makes the high-output 3-phase stator the most obvious choice(?); 3-phase reg./rec. already fitted, new 3-phase or single-phase stator can be connected; thumbsup only single-phase reg./rec. fitted (e.g. Tympanium), either you're limited to single-phase stators or you have to replace the reg./rec. too. thumbsdown

If you have/decide to replace the rectifier and Zener with a reg./rec.:-connect the reg./rec. DC wires directly to the corresponding battery terminals, not in place of the old rectifier or Zener connections. I put an automotive blade fuse/holder in one of the wires between battery and reg./rec., to preclude any possibility of a fault in the reg./rec. causing a short-circuit.
. connect the reg./rec. DC+ Red wire to the battery +ve terminal;

. connect the reg./rec. DC- wire (Ebay Honda reg./rec. Green wire, Podtronics Black wire) to the Brown/White wire originally connected to the rectifier's centre plate, the bike's Ammeter will continue to show both charge into and discharge from the battery.


1 member likes this
#839672 Feb 11th a 12:26 AM
by NickL
15 volts + will shorten the life of your battery.
As that is a digital meter, it may be a little misleading too.
Better to test with a decent analogue type meter.
1 member likes this
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