BSA b50 Boyer

baz

baz

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I have been considering fitting a royal Enfield micro mk111 ignition to my b50 motor
I'm wondering if any of you learned people out there could take a look at the spec below and tell me if it's suitable
And because I have one on the shelf!! :D

The b50 timing should be 34° full advance




Thank you for your inquiry.

The operating electronic advance is approx 8 Deg. camshaft, (16 Deg. crankshaft) between 1000-5000 rpms. Total advance including retardation for starting is approx 36 Deg crankshaft.

Regards,
Boyer Bransden.

---
Boyer Bransden Electronics Ltd
Frindsbury House
Cox Street
Detling
Maidstone
Kent
ME14 3HE
Tel: 0044 (0)1622 730939
Fax: 0044 (0)1622 730930
 
The MK3 suffers from over advanced timing when battery voltage is low such as after 2 or 3 weeks in the garage. So unless you plan to be certain the battery is recharged before the first kick expect some kickback. MK4 cures this, Pazon also has this cure but then it also does not like big singles due to its odd wake up from sleeping procedure so Boyer MK4 is better in this instance.
 
kommando said:
The MK3 suffers from over advanced timing when battery voltage is low such as after 2 or 3 weeks in the garage. So unless you plan to be certain the battery is recharged before the first kick expect some kickback. MK4 cures this, Pazon also has this cure but then it also does not like big singles due to its odd wake up from sleeping procedure so Boyer MK4 is better in this instance.
Click to expand...
What do you think of the advance? I'm a complete layman/dunce when it comes to this
Good info about the MK3 I didn't know they'd cured it with the MK4
I also have a MK3 for unit singles on the shelf amongst others
I was wondering if the Enfield one would be better on a b50 that was all
Cheers
 
I just fit Boyer boxes regardless of what it says on the box ref models as they are pretty much all the same other than the variation in timing caused by the tolerances in the electronic parts which means you must strobe to be sure of the fully advanced point is correct.
 
If the Boyer switches itself off after a couple of seconds, then doesn’t spark until the second impulse it gets from the trigger, your B50 might not start.
 
Well so far so good
I went ahead and fitted royal Enfield Boyer and the bike started first kick
Idled perfectly and revved out
You can now blip the throttle and the revs settle back immediately
Unlike the points setup
I checked the full advance with a strobe lamp and revved it until it stopped advancing
It was easy to see it advance with the electronic ignition when I did this with the AAU the timing mark was jumping all over the place!!!
I restarted it several times with no sign of a kickback
I'll just have to make sure I keep the battery tip top
 
Triton Thrasher said:
A “first kick” B50 is a good B50!
Click to expand...
I was a bit surprised!!
I kicked it through a couple of times with the decompressor pulled
Then eased it over tdc until I felt the exhaust valve start to open
Then one kick and it went ,the motor even sounds a bit different
But I could be imagining that!!!
 
kommando said:
The MK3 suffers from over advanced timing when battery voltage is low such as after 2 or 3 weeks in the garage. So unless you plan to be certain the battery is recharged before the first kick expect some kickback. MK4 cures this, Pazon also has this cure but then it also does not like big singles due to its odd wake up from sleeping procedure so Boyer MK4 is better in this instance.
Click to expand...
Just how low dose the voltage have to be before the Boyer goes to full advance?
Yesterday it was fine, starting fine and today it kicked me back
I don't know what the voltage was yesterday but today when it kicked back it was 12.66 v
Is that low enough to go full advance?
Cheers
 
baz said:
But mine was at 12.66 and it was kicking back every time I tried to start it
Click to expand...

Maybe look for a bad electrical connection, poor ignition switch contacts, etc.?

Try running jumper wires (- & +) from the battery directly to the Boyer?
 
L.A.B. said:
Maybe look for a bad electrical connection, poor ignition switch contacts, etc.?

Try running jumper wires (- & +) from the battery directly to the Boyer?
Click to expand...
What's really puzzling me is the difference between yesterday and today!
It showed no signs of kicking back yesterday ,it started very easily I even deliberately half heartedly kicked it over just to see if it'd kick back but nothing
Then today even bringing it up to compression it was kicking back
I turned the stator plate as retarded as I could which was half the slot and it made no noticeable difference
It's really done my ankle in!!! FFS
 
Even though its less severe the Boyer has a sleep function which it goes into after 4 or 5 sec of receiving no signal from the timing stator, to awake it only needs one signal, unlike the pazon which needs two, but on a big single with light flywheels and low kickstart gearing this sleep function it could still have an affect. So if you switch the ignition on just before kicking this should negate it. The other trick on the B50 is to kick it like it is a Velo and instead of just getting it over TDC progress the piston further before kicking. The theory being that with the low kickstart gearing the flywheels have less time to slow down if the piston is further on before kicking. Or get a B44, bigger flywheels, lower compression, smaller capacity but same too low kickstart gearing.
 
kommando said:
Even though its less severe the Boyer has a sleep function which it goes into after 4 or 5 sec of receiving no signal from the timing stator, to awake it only needs one signal, unlike the pazon which needs two, but on a big single with light flywheels and low kickstart gearing this sleep function it could still have an affect. So if you switch the ignition on just before kicking this should negate it. The other trick on the B50 is to kick it like it is a Velo and instead of just getting it over TDC progress the piston further before kicking. The theory being that with the low kickstart gearing the flywheels have less time to slow down if the piston is further on before kicking. Or get a B44, bigger flywheels, lower compression, smaller capacity but same too low kickstart gearing.
Click to expand...
I'm not understanding the sleep function
When I start it I tickle it until it floods
I turn the ignition on
I kick it through 2 or 3 times with the valve lifter pulled I can see the ammeter flick as the rotor passes the pickups
I get it past tdc until I can feel through the valve lifter lever that the exhaust rocker has started to move
Return the kickstart to the top and kick it through
That's when it gave me an almighty kickback
I tried to start it again but every time I brought it up to feel where tdc was before pulling the valve lifter it kicked back
I had been using the same procedure the day before and the bike was starting right with no sign of any kickback!
I checked the voltage at the battery with the ignition off it was 12.66v
I won't be able to kick it for a few days now ,my ankle is not right
I don't know whether to invest in a MK4 Boyer
Refit the AAU unit and try to get it working , maybe stronger springs
Or try some other ignition?
I can't risk this injury again
 
baz said:
I tried to start it again but every time I brought it up to feel where tdc was before pulling the valve lifter it kicked back
Click to expand...
This is due to the procedure you are using is making sure the boyer does not go to sleep and the boyer sees the slow movement as a kick not a slow movement.

So try this, do not turn the ignition on until the piston is just past TDC, so with the ignition off as you pass TDC there will be no spark and no kickback. Then turn the ignition on and take the full blooded kick.
 

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