BSA b44/50

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What I like about your bike is that it is built with period parts, just how it could have been built in the early seventies.
 

baz

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I've got to the wiring stage on this project
I decided to use a new unused Boyer power box reg/rectifier that I've had on the shelf for years thinking this could be an advantage having the built in capiciter as back up (although I will always be using a battery ) I have wired the bike negative earth
Unfortunately the regulator rectifier won't work
I've connected the two yellow wires to the alternator
And the red to positive black to negative on the battery and nothing
I tried connecting the black/yellow wire to the negative still nothing IE not charging
I've heard the capiciter can break down with age on these units if so can this affect the reg/rectifier side of the unit?
 
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The issue with the powerbox is the internal capacitor is life limited the same as the Lucas 2MC, so depending on how it fails it may strand you but with no way of getting at it. Sounds like it has failed that way.
 

baz

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The issue with the powerbox is the internal capacitor is life limited the same as the Lucas 2MC, so depending on how it fails it may strand you but with no way of getting at it. Sounds like it has failed that way.
It's looking that way
I ran out of time yesterday when I was testing it
But I'll test the alternator AC output and I'll try a spare reg/rectifier and if all is well I'll bin the powerbox
I liked the Idea of the capacitor and the delayed lighting function as I'm running points ignition I thought it'd work well
I've had the powerbox on the shelf for maybe 8 years
 
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I've had the powerbox on the shelf for maybe 8 years
That is what possibly killed it. I never recommend fitting them for that reason, even with a fully charged battery it can strand you, at least with the 2MC you can get to it and disconnect it.
 

baz

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That is what possibly killed it. I never recommend fitting them for that reason, even with a fully charged battery it can strand you, at least with the 2MC you can get to it and disconnect it.
I may cut it open before I bin it just to have a look
I'm assuming it's potted inside the metal case
 
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I'm assuming it's potted inside the metal case
Yes, its the biggest can, once cut out and nothing else damaged it should revert to a reg/rect, not sure if the delayed lighting will still function or even if that failed would the whole box be taken out.
 

baz

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This is strange
I tried a known good reg/rectifier and all was well charging as it should
Then I re tried the Boyer power box and that is now working fine!!!
Maybe it's my dodgy wiring!? But it's definitely working now
Just got to decide if I trust it or not!!!
 

grandpaul

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Old Boyer ignitions have a nasty habit of fooling you into thinking they work until you reach the farthest point from home and they die again.
 

baz

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Old Boyer ignitions have a nasty habit of fooling you into thinking they work until you reach the farthest point from home and they die again.
It's not an ignition unit it's a regulator/rectifier power box
It contains a capicitor for running without a battery
 
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As long as you carry the tools to de-pot the powerbox and remove the capacitor you will be fine.

But that tool bag is getting rather large ;)
 
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Fast Eddie

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This is strange
I tried a known good reg/rectifier and all was well charging as it should
Then I re tried the Boyer power box and that is now working fine!!!
Maybe it's my dodgy wiring!? But it's definitely working now
Just got to decide if I trust it or not!!!

Not worth the risk IMHO. As is well proven by the Law of Sod.

I‘d at least remove the suspect capacitor, or, given the relative low cost of other options, replace the whole thing.
 

baz

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Not worth the risk IMHO. As is well proven by the Law of Sod.

I‘d at least remove the suspect capacitor, or, given the relative low cost of other options, replace the whole thing.
Yep it's a bit of a dilemma I don't really want to bin a brand new unit albeit sitting on my shelf for 8 years and appears to function correctly
Or run with another unit that I know to be good
I have room for both units so I may simply bolt the other one on and swap wires if it conks
Dunno yet
 
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Have rec/rec, capacitor and BSM from Paul Goff on the B40WD. Works great. Starts without battery and keeps battery charged with lights on.
 
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baz

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Have rec/rec, capacitor and BSM from Paul Goff on the B40WD. Works great. Starts without battery and keeps battery charged with lights on.
I used to run a b40 with a 2mc cap , rectifier,zener without a battery
 
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