B25/B44 wiring

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B25/B44 wiring

Post by blaise » Sun Jun 09, 2013 3:15 pm

I am about to start sorting out the wiring of my 1969 B25, with 1968 B44 motor.

The stock wiring is mostly intact.

The speedometer was missing when I bought the bike, and I do not plan to replace it for now.

The original Lucas headlight was shattered, so I plan to use a sealed beam, so the "pilot" light will not be present.

The horn button was also missing, so I will not run the horn, for now.

I am going to run a Shorai lithium-iron battery. Small, light and spill proof.

I will run a Pazon Sure-Fire (PA1) ignition. 

Here is the wiring diagram that I put together in my planning.  The deleted circuits are noted in pencil, and the original coil, points, mechanical advance and condenser will be omitted:

Image

Did I get anything wrong?

Should I do anything with the rectifier or zenith diode?

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Re: B25/B44 wiring

Post by gunnag » Sun Jun 09, 2013 3:46 pm

Diagram looks good to me, but then IM not an electrical expert, I would remove the original coil as suggested.

I would replace the zenor diode and rectifier with a solid state podrtonics type, see Link The original setup works OK but after 30 years the zenor can leak current and the rectifier may be on the way out.

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Re: B25/B44 wiring

Post by skippy » Sun Jun 09, 2013 11:24 pm

I have found the Dyna coil works good with the pazon ignition.
There is a lot of excess wiring on our bikes.
Doug
Should never have sold them old motorbikes

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Re: B25/B44 wiring

Post by minetymenace » Mon Jun 10, 2013 12:38 am

Brace yourself for a bit of a geeky post.

LiFePO4 batteries have a higher cell voltage than PbSO4 so a 12v block will probably be made of 4 cells. While they have a fairly broad float charge range, from memory the ideal float charge is about a volt hogher than a six cell PbSO4 block. If you want to raise the charge voltage a little, you could put a high current diode in (inverse) series with the zener, and increase the regulation voltage by 0.7v. This would make the charge voltage nearly perfek. If you were worried that this might over volt other stuff, you could put another diode in series with the ignition wire to drop it back down again (not sure if this is clear, might have to do a drawing).

If you are replacing the rectifier and want to get all there is to get out of the alternator, with three wires fit a three phase rectifier (won't make much difference especialy with no headlamp or horne).

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Re: B25/B44 wiring

Post by blaise » Tue Jun 11, 2013 9:29 am

Thank you kindly for the responses. I think the solid state regulator/rectifier is a good idea.  I was recommended the Tympanium unit as well.  Any reason not to go that route?

Minetymenace, thank you for the technical tips.  I am afraid that your recommendations are a bit beyond my current abilities.

I updated and cleaned up my wiring diagram.

Image

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Re: B25/B44 wiring

Post by blaise » Mon Jun 17, 2013 10:15 pm

I think that I have most of the wires dry run (not wrapped yet), and can account for most of the wires that I took out and remain on my bench.....except for two.

These are a couple of wires that were NOT hooked up when I got the bike.

They run from the headlight shell to near the original location of the rectifier.

One is green/white and the other is green/red.

Anyone know what these were for?

Seen in the top left of this photo:
Image

Close up of these (combo connector is to tail light):
Image

In the headlight shell, they are the double female bullet connectors in the center:
Image

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Re: B25/B44 wiring

Post by steve m » Tue Jun 18, 2013 3:39 am

Indicators :?:

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Re: B25/B44 wiring

Post by Canberra » Tue Jun 18, 2013 4:15 am

Definately indicators. I believe Lucas used the same colours on all their wiring of that era.

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Re: B25/B44 wiring

Post by blaise » Tue Jun 18, 2013 7:20 pm

Interesting, I see no other signs of turn signals. Thanks

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Re: B25/B44 wiring

Post by kommando » Tue Jun 18, 2013 8:31 pm

1970 (and 69 possibly) harnesses had the wires for indicators but not the indicators, even the new harnesses available today have the extra wires.

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Re: B25/B44 wiring

Post by Mark Cook » Tue Jun 18, 2013 8:59 pm

Made perfect sense to me Gerry
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Re: B25/B44 wiring

Post by blaise » Tue Jun 18, 2013 10:42 pm

Thanks guys

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Re: B25/B44 wiring

Post by B44Claus » Mon Jun 03, 2019 7:53 pm

Good evening,
I'm rewiring my B25 Starfire and was looking for a modified wiring diagram to work with a Lucas electronic rectifier. I fell over this thread and thinks the wiring diagram is probably what I need. I was just speculating if the battery could discharge through the alternator when the bike is parked for a period?


brgds,
Claus
B44Claus

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Re: B25/B44 wiring

Post by kommando » Mon Jun 03, 2019 8:03 pm

Not sure how, I know my Wassell rectifier/regulator leaks to earth and discharges the battery on my Commando with the ignition off but that's because it's crap and I have a replacement not because the wiring is defective.

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Re: B25/B44 wiring

Post by B44Claus » Mon Jun 03, 2019 8:26 pm

Thanks Commando,
That was exactly my concern with the regulator connected on the battery side of the ignition switch.
Anyway, it shouldn't be an issue if the regulator is OK.

Brgds,
Claus
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