Carb settings.......

I followed the Boyer instructions virtually to the letter. The reason I stated they were a mystery to me is because they are pretty inaccurate . They are though easy to follow,I was being sarcastic ( sorry I’ve been on UKGser too long!)I haven’t yet checked to see how accurate the scale in the primary cover is with a degree wheel. However the timing was initially set with the 28 degree btdc crank mark which matched perfectly to the primary cover scale, so would assume it’s pretty close.

Got you. A Mk 111.

I am not familiar with their timing methodology but I understand there is a separate timing setting

JOHNO23 said:

I followed the Boyer instructions virtually to the letter. The reason I stated they were a mystery to me is because they are pretty inaccurate .

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If the rotor is positioned according to the instructions with the paint dot visible in the hole then correct ignition timing is usually attainable within the available slot range. I haven't found a Boyer to be that inaccurate.

johnm said:

I am not familiar with their timing methodology but I understand there is a separate timing setting

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The Mk3 crankshaft has a slot (normally) that lines up with a timing hole at 28 degrees BTDC.

L.A.B. said:

If the rotor is positioned according to the instructions with the paint dot visible in the hole then correct ignition timing is usually attainable within the available slot range. I haven't found a Boyer to be that inaccurate.



The Mk3 crankshaft has a slot (normally) that lines up with a timing hole at 28 degrees BTDC.

Click to expand...

That’s what I did, the mark was correctly slightly advanced of the 28degrees, so I then checked it against the scale and it was spot on virtually.........

dynodave said:

They look like the metal tab is a stamped piece. On the upper lip opening you can see the white line on the edged which is classic rounding of the punch press sheared edge.
The while line is the concentrated reflection from rounded edge and on the other side is a ragged ass edge like a microscopic razor blade/hack saw blade. It can then grab the round step of the needle and not allow sliding. I use a 12 ton punch press making a part for my starter out of 16g stainless. so for over ten years I have to examine the results.
I can easily see why the dressing deburring can stop the problem.
JohnM
you have a good guy there!
and Thanx for the pix
Sounds like a AMAL- AH HA moment....... probably see this again until they start batch/tumble deburr these things

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Or they sharpen/adjust die clearance.

I had a Boyer setup installed on a B44 and fully strobed as per the instructions, as part of a fault finding exercise I swapped boxes but left everything else untouched eg the stator and rotor. On starting the bike the exhaust pipe immediately turned blue and a quick re-strobe showed it was out by 8 degrees and was badly retarded. The strobing step in the instructions is not optional, it must be done, the variation between boxes means the static timing is only good for the first start up.

L.A.B. said:

If the rotor is positioned according to the instructions with the paint dot visible in the hole then correct ignition timing is usually attainable within the available slot range. I haven't found a Boyer to be that inaccurate.



The Mk3 crankshaft has a slot (normally) that lines up with a timing hole at 28 degrees BTDC.

Click to expand...

Submitted by Ashley Cutler on Mon, 13/04/2020

The slot in the crank is…
The slot in the crank is actually 30 BTDC.

This from an NOC post.... Any comment?

kommando said:

I had a Boyer setup installed on a B44 and fully strobed as per the instructions, as part of a fault finding exercise I swapped boxes but left everything else untouched eg the stator and rotor. On starting the bike the exhaust pipe immediately turned blue and a quick re-strobe showed it was out by 8 degrees and was badly retarded. The strobing step in the instructions is not optional, it must be done, the variation between boxes means the static timing is only good for the first start up.

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The concepts that Kommando brings up are not new. Both the boxes and magnet/coil pick-ups are subject to manufacturing variation based on normal electronic component tolerances classes and the gaussing process of the magnets.
The chosen process by boyer is to standardize the high rpm results and ignore the starting advance and cruising advance as "unobtainable" by nature... and is the result of this product type.

The "dot in the hole" is quite bad as stated. When tested on my distributo machine for accurate results to obtain a improved method, I found the dot heavily skewed within the hole and once I adopted the new position for installation, I had later installed several systems without a need to readjust. But that was LONG ago and have not kept records.

For a particular system, box and pickup, Once you adjust @ 5000 rpm, immediately go to 2000 and take a data point and write it down. That can be your future calibrated system data if it is removed and must be set up again. It will NOT be reliable if box or pick-up is changed.

One of the advantages of the Tri Spark is the LED static timing function which, in my experience at least, gets the timing cock on (except once when I forgot the Norton cam goes backwards, which is hardly Tri Sparks fault) !

Have you checked that the alternator rotor center is not loose from the rotor? The timing mark can be off a lot if it is.

JOHNO23 said:

That’s what I did, the mark was correctly slightly advanced of the 28degrees, so I then checked it against the scale and it was spot on virtually.........

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Oh well, at least you found what the problem was.

EstuaryBoy said:

Submitted by Ashley Cutler on Mon, 13/04/2020

The slot in the crank is…
The slot in the crank is actually 30 BTDC.

This from an NOC post.... Any comment?

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Well...after a lot of messing about with a degree disc and making a new piston stop (couldn't find the old one!)...
...this is 30 degrees...

...and this is 28....

...so whether it's supposed to be 28 or 30 it's about a degree out on my Mk3.

L.A.B. said:

Oh well, at least you found what the problem was.


Well...after a lot of messing about with a degree disc and making a new piston stop (couldn't find the old one!)...
...this is 30 degrees...

...and this is 28....

...so whether it's supposed to be 28 or 30 it's about a degree out on my Mk3.

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When you put it in the middle (29 degrees), what does the timing scale show? If not 29 degrees, you can adjust it on a MKIII. If way off, then I bet your alternator rotor is bad.

marshg246 said:

When you put it in the middle (29 degrees), what does the timing scale show?

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28 degrees.

If it's a degree (or even two degrees) out then I'm not going to panic as the Pazon is set at 28 degrees.

marshg246 said:

If not 29 degrees, you can adjust it on a MKIII.

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Yes, I know.

marshg246 said:

If way off, then I bet your alternator rotor is bad.

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My understanding has always been that the crank slot was at 28 degrees BTDC and 28 degrees on the timing scale is where the rotor mark lines up. If I adjusted the scale then it could be getting on for twenty years ago so I have to admit I can't remember.

L.A.B. said:

28 degrees.

If it's a degree (or even two degrees) out then I'm not going to panic as the Pazon is set at 28 degrees.

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100% agree. He was saying, if I understand correctly, that the timing mark was way off. If so then it could be a bad rotor center. I complicated it more than need be with the 29 degrees - my point was is the timing scale correct (is the rotor OK)?

marshg246 said:

He was saying, if I understand correctly, that the timing mark was way off.

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"Way off" because the static timing setting was somehow way off.

When finally strobed and the timing readjusted (apparently using the same timing marks) the bike then "ran great and ticked over and picked up beautifully.".

OK, you got me (nothing new )

'Don't touch the jetting until you have the timing set' is good advice.
Advancing the timing can have the same effect as leaning-off the jetting. If you have checked the floats are not sinking due to a hole in them and your idle circuit is clear - with a slide cutaway of 3.5 or 3 mm, the needle jet ID with petrol as fuel should be either 0.106 inch or 0.107 inch. Lowering the needles leans the mixture, raising them richens it. If you fit 0.106 needle jets and use needles with the clip in the bottom groove, that is the richest setting with the leanest needle jet. If you run the motor, it should run clean but sluggish. As you progressively lower the needles, by raising the clips, you will reach a point where the motor 'coughs' as you open the throttle, especially as you ride the bike changing up through the gears. When you reach that point, raise the needles one notch. If you are running an open exhaust system, you might need 0,107 inch ID needle jets to get clean running - repeat the same procedure with the needles. - Lower them until you get the cough, then come back one

Getting the needles and needle jets right is critical, if you want good performance. The ignition timing should be set and forget. Even if the ignition timing is slightly wrong for the fuel you are using, you jet to it - so everything is usually OK.
If your jetting is right, your bike should be a pig to ride on a very cold morning - but great at every other time. If it runs perfectly in the extreme cold when the chokes are off, you are probably too rich with the needles.