Boyer Bransden timing and stator plate adjustement problem

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Thomasdunstall

Thomasdunstall

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After the good results obtained adjusting the timing on my '72 Roadster
this morning we're trying to adjuste the timing on the '71 Fastback golden bronze we've fully rebuild
it was an easy job on the Roadster

we found a problem with the Fastback:
it is also fitted out with a MKIV boyer bransden electronic ignition
revving the bike we have 33° at 3.000 rpm, 36° at 4.000 rpm and 39° at 5.000 rpm
there is no way to rotate the stator plate to gain 31° BTDC
I mean, the correct timing is not obtainable moving the stator plate, there's no more space on adjustment
how can we solve this problem?

please advice
Thanks Thomas and Piero (who's workin' on the bike while I'm writin' :D )
 
Re: Boyer Bransden timing and stator plate adjustement probl

Thomasdunstall said:
I mean, the correct timing is not obtainable moving the stator plate, there's no more space on adjustment
how can we solve this problem?
Click to expand...

You need to remove the Boyer rotor and reposition it. From your description the rotor seems too far advanced.
 
Re: Boyer Bransden timing and stator plate adjustement probl

Remove the magnet rotor from the cam (remove retaining bolt and gently tap bolt side ways to break the seal with the taper in the cam) and rotate rotor 5 or so degrees in the oposite direction to which the cam normally rotates (can't remember off the top of my head which way that is) and retighten bolt. Start engine and recheck timing.
 
Re: Boyer Bransden timing and stator plate adjustement probl

L.A.B. said:
Thomasdunstall said:
I mean, the correct timing is not obtainable moving the stator plate, there's no more space on adjustment
how can we solve this problem?
Click to expand...

You need to remove the Boyer rotor and reposition it. From your description the rotor seems too far advanced.
Click to expand...

from TDC we adjusted the timing 31° before with a degrees disc
then we put the rotor as in the istruction as the mark on the timing
Boyer Bransden timing and stator plate adjustement problem


and than we put the stator plate
Boyer Bransden timing and stator plate adjustement problem


Do you think we've to move the rotor? not the stator plate?
Boyer instrucrtion said to remove a small amount from the plate until you can obtain a correct timing
 
Re: Boyer Bransden timing and stator plate adjustement probl

yes, center the plate in the slots. Then move magnets till red dot is in center of the hole (second picture). With timing mark @ 31 degrees. This will be a good starting point. Then as a lot of guys do finally adjustment is made by test rides. You should be within a couple of degrees either way. I just set mine @ 30-31 works for me
 
Re: Boyer Bransden timing and stator plate adjustement probl

Thomasdunstall said:
Do you think we've to move the rotor? not the stator plate?
Click to expand...

Yes, if the correct timing cannot be set within the range of the Boyer stator plate adjustment slots, then the rotor needs to be repositioned.
 
Re: Boyer Bransden timing and stator plate adjustement probl

Deets55 said:
yes, center the plate in the slots. Then move magnets till red dot is in center of the hole (second picture). With timing mark @ 31 degrees. This will be a good starting point. Then as a lot of guys do finally adjustment is made by test rides. You should be within a couple of degrees either way. I just set mine @ 30-31 works for me
Click to expand...

I can't set on 31° moving the plate I can only reach 39 at 5.000 mo more space on adjuster
i've two chance or work on the plate removing materials or move the rotor
but instructions said to work on stator plate not to move the rotor, it must be keept in place on the mark on timing
 
Re: Boyer Bransden timing and stator plate adjustement probl

Thomasdunstall said:
but instructions said to work on stator plate not to move the rotor, it must be keept in place on the mark on timing
Click to expand...

The Boyer instructions do not say that.
It says:
http://www.boyerbransden.com/pdf/KIT000 ... 00017_.pdf
If the timing is not obtainable before the end of the adjustment, the magnetic rotor will have
to be slackened off and moved a small amount until the correct timing can be obtained.
Click to expand...

So, you need to remove the rotor and reposition it.
 
Re: Boyer Bransden timing and stator plate adjustement probl

Listen. Remove plate . Re position rotor. Put plate back in. Move plate until it just stops kickbackings from starting attempts , that's your sweet spot. Test drives too. No real need to strobe it. Good luck. :)
 
Re: Boyer Bransden timing and stator plate adjustement probl

L.A.B. said:
Thomasdunstall said:
So, you need to remove the rotor and reposition it.
Click to expand...
Click to expand...

Hi Les,
I will do.
I will start from static setting 31degrees, then i will rotate (clockwise i think!!!!) the rotor for some degrees; is that correct ?
Thank you.
Piero

P.S.: Why is there this difference between the bike of Mario (roadster) and Luigi (fastback) that had the same setting?
 
Re: Boyer Bransden timing and stator plate adjustement probl

L.A.B. said:
Thomasdunstall said:
but instructions said to work on stator plate not to move the rotor, it must be keept in place on the mark on timing
Click to expand...

The Boyer instructions do not say that.
It says:
http://www.boyerbransden.com/pdf/KIT000 ... 00017_.pdf
If the timing is not obtainable before the end of the adjustment, the magnetic rotor will have
to be slackened off and moved a small amount until the correct timing can be obtained.
Click to expand...

So, you need to remove the rotor and reposition it.
Click to expand...

:shock: yes Les you're right sorry :roll:
some misunderstanding :D :D :D
 
Re: Boyer Bransden timing and stator plate adjustement probl

I have found that if I line up the Boyer magnetic rotor with the Norton logo on the timing cover (as the Boyer instructions state) it will be too advanced, so I bias the rotor slightly clockwise from the logo. Like 9:30/3:30 o'clock. This should give enough stator movement to retard/advance when dialing it in with the strobe.
 
Re: Boyer Bransden timing and stator plate adjustement probl

pierodn said:
I will rotate (anticlock i think!!!!) the rotor for some degrees;
Click to expand...

The camshaft and rotor turn anticlockwise, therefore the rotor needs to be moved clockwise in relation to the camshaft in order to retard it, which seems to be what is required (and which is the opposite direction you would normally turn the stator plate to 'retard' the timing).


pierodn said:
but then the timing hole of the stator plate needs to center the rotor's dot again?.
Click to expand...

Yes.

I also suggest that you disregard the illustration that shows the rotor magnets in line with the NORTON name, as I do not consider it to be accurate.
 
Re: Boyer Bransden timing and stator plate adjustement probl

Once it's all set up where you want it, the next time before you pull it apart, put the engine at T.D.C. and put a scribe mark from the rotor to the engine case to give you a quick reference for the next time you need to assemble it.
 
Re: Boyer Bransden timing and stator plate adjustement probl

pierodn said:
Why is there this difference between the bike of Mario (roadster) and Luigi (fastback) that had the same setting?
Click to expand...

Setting the Boyer ignition timing statically is not very accurate, so the timing can easily be anything up to 10 degrees out initially (or perhaps sometimes even more than that?) and every 1 degree of error at the pickup will be double the amount at the crank.
All the static setting really allows you to do, is to (hopefully) set the timing close enough so the engine will start, once the engine can be started, then the actual ignition timing is done using the strobe.
 
Re: Boyer Bransden timing and stator plate adjustement probl

Hi Les,
Today I use the strobe on my bike with a Pazon which had only a static setting to 31 degrees.
The result was 31 degrees to 4000 RPM.
Ciao
Piero
 
Re: Boyer Bransden timing and stator plate adjustement probl

pierodn said:
Today I use the strobe on my bike with a Pazon which had only a static setting to 31 degrees.
The result was 31 degrees to 4000 RPM.
Click to expand...

OK, so that's one set correctly out of three. :?
It's possible the Pazon can be set more accurately, statically, although you might just have been lucky, but the Pazon instructions still say to finally strobe the ignition.
Using a white light strobe, time the engine to the full advance mark (previously used in step 19) with the engine running up to 4000rpm
Click to expand...

They are not telling you this just to waste your time, or increase sales of strobe lamps, strobing not only confirms that the ignition is (or is not) set accurately but also that it is advancing and retarding correctly.
 
Re: Boyer Bransden timing and stator plate adjustement probl

Hi Les,
Is the same thing use the strobo on the left or on the right lead's coil?.
Ciao
Piero
 
Re: Boyer Bransden timing and stator plate adjustement probl

pierodn said:
Is the same thing use the strobo on the left or on the right lead's coil?.
Click to expand...

Yes, on a wasted spark system such as Boyer or Pazon both sides spark simultaneously, so it doesn't matter which side the strobe is connected to.
 
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