Ignition Timing Setup Boyer

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The other reason to check the rotor is that if it is loose it's only going to get worse.
 
No the srobe was not being used that is how miserable my degree scale was printed.
 
montelatici said:
If there is enough slop in a crank to make TDC an issue when a piston is at TDC, then you need a new crank and bearings.
Click to expand...

The reality is that there has to be crankshaft movement while the piston is at TDC. So it totally depends on the accuracy you are seeking. You can 'find' TDC by: holding your thumb/finger in the spark plug hole and feeling when compression stops; you can 'find' TDC sticking a pencil/screwdriver/whatever in the spark plug hole and observing the point where it stops moving; you can use a bubble as described. Depending on what you are trying to do, any of those methods can work perfectly well.

Yes, you can misread a degree wheel or do the math badly but it's about as basic as math gets...determining 1/2 of a number. The biggest IN-accuracy issue using a piston stop/degree wheel involves the size of the wheel and the diameter of the pointer. If you print out a 4 1/2" 'degree wheel' from the internet and adhere it to a CD - which seems to be a fairly common recommendation - and use a piece of 12 Gauge Romex copper ground wire as your pointer, you have very closely-spaced indices and a pointer that will probably cover 4 degrees! Heck, it's probably LESS accurate than watching the pencil move up and down! :) OTOH, a 12" Moroso wheel with a sharp pointer will be dead-nuts accurate.

I am NOT saying that other methods don't work but on an accuracy scale, the degree wheel/piston stop is the most accurate. Yes, I admit that assumes it's a decent sized wheel/pointer and the operator knows how to do it. ;)
 
Woody850 said:
No the srobe was not being used that is how miserable my degree scale was printed.
Click to expand...

So buy and fit a new one taking time to ensure the marks align correctly, the holes in the scale can be opened out to allow the scale to be moved around more if required.
 
:)
MexicoMike said:
The reality is that there has to be crankshaft movement while the piston is at TDC. So it totally depends on the accuracy you are seeking. You can 'find' TDC by: holding your thumb/finger in the spark plug hole and feeling when compression stops; you can 'find' TDC sticking a pencil/screwdriver/whatever in the spark plug hole and observing the point where it stops moving; you can use a bubble as described. Depending on what you are trying to do, any of those methods can work perfectly well.

Yes, you can misread a degree wheel or do the math badly but it's about as basic as math gets...determining 1/2 of a number. The biggest IN-accuracy issue using a piston stop/degree wheel involves the size of the wheel and the diameter of the pointer. If you print out a 4 1/2" 'degree wheel' from the internet and adhere it to a CD - which seems to be a fairly common recommendation - and use a piece of 12 Gauge Romex copper ground wire as your pointer, you have very closely-spaced indices and a pointer that will probably cover 4 degrees! Heck, it's probably LESS accurate than watching the pencil move up and down! :) OTOH, a 12" Moroso wheel with a sharp pointer will be dead-nuts accurate.

I am NOT saying that other methods don't work but on an accuracy scale, the degree wheel/piston stop is the most accurate. Yes, I admit that assumes it's a decent sized wheel/pointer and the operator knows how to do it. ;)
Click to expand...
Once you have done all of this you ride it up a hill and advance the timing until it pinks then back it off a little!!:)
 
Woody850 said:
No the srobe was not being used that is how miserable my degree scale was printed.
Click to expand...

OK, thanks. My apologies then, as it's not what I thought I was seeing. If the bike runs OK, and your only concern is the scale being out a couple of degrees when it's known to be set to 31 degrees BTDC then as kommando says, correct the scale.

The 850 Mk3 scale has a small range of adjustment, however, I'm not sure if it fits (or can be made to fit) earlier models?
https://andover-norton.co.uk/en/shop-details/16351/ignition-timing-degree-scale-850-mk3-only-
 
L.A.B. said:
The 850 Mk3 scale has a small range of adjustment, however, I'm not sure if it fits (or can be made to fit) earlier models?
https://andover-norton.co.uk/en/shop-details/16351/ignition-timing-degree-scale-850-mk3-only-
Click to expand...

It does as I have used one but it will stand well clear of the rotor and introduce possibility or reading it wrong due to parallax errors if you do not have you head directly in front of the scale. I was moving the rotor outwards so it suited my setup.
 
baz said:
:)
Once you have done all of this you ride it up a hill and advance the timing until it pinks then back it off a little!!:)
Click to expand...

Probably the best practical method for getting the optimum performance from a specific bike! :)
 
This morning I spoke to Joe Seifert and ordered a new scale and the tool to set it up (re. Kommando). In the mean time there is time to run further checks.
 
Calibration of parts?
1. Is the crank keyway cut correctly in relation to the crank throw?
2 Is the alternator marked exactically 180 degree from the center of the rotor keyway?
3. Are the 3 holes for the inner primary drill exact?
4. Is the outer primaries 2 timing mark mounting holes accurate?
5. As mentioned by kommando: The 1/8" holes can be made into slots to calibrate the whole mess.....LOL
In reality you can bend the legs a bit to advance or retard the markers 2-3 degrees max
Note: on the center marker only that it had been punched to raise a little bump to show the 28 degree line on the front a little taller.
Ignition Timing Setup Boyer


All to "calibrate" a "boyer" (which one???) which are, unit to unit for analog, shown in field testing to be a very unrepeatable curve.
 
baz said:
Once you have done all of this you ride it up a hill and advance the timing until it pinks then back it off a little!!:)
Click to expand...

In reality you are just throwing darts at the dart board when timing a lot of thes ignitions.
None of us run constantly and only at 5000 rpm.
You are setting it up like this (but then altering it):
Ignition Timing Setup Boyer

Because they are made like this:
Ignition Timing Setup Boyer


Good luck;)
So in reality the "indicated" number is not actually important but just a stable and repeatable indication so changes can be noted and repeated if desired. IMO
 
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If you get the ignition timing wrong in the advance direction and your carbs are jetted lean, you can get the situation where you start burning pistons and valves. I usually set the ignition timing first, then jet to suit it. Where the timing actually is, is not as important as having it remain the same. Because a increase in advance has a similar effect to leaning-off the jetting. Most of your road bikes are probably jetted slightly too rich, so a slight advance error might not matter much. With my Seeley 850, if I lower the needles one notch, it is obviously too lean and I know immediately, because of the cough when I ride the bike. I always use main jets which are slightly too large anyway. I always try to avoid disturbing the position of the Boyer rotor. If I have to do that, I'm always careful to check the jetting afterwards.
Because you guys are using petrol as fuel, when you tune for best performance you have much less leeway for error than I do. I use methanol which has unlimited anti-knock and because my motor is only on 9 to 1 comp. , I add 4 degrees to the ignition advance and jet to that. That 29 degrees advance which is specified by the factory, is probably for the worst kind of petrol which was commonly available in 1970.
 
I don't use factory marks when setting ignition advance or cam timings on any bike - only ever a degree disc and sometimes a dial micrometer.
 
MexicoMike said:
The reality is that there has to be crankshaft movement while the piston is at TDC. So it totally depends on the accuracy you are seeking. You can 'find' TDC by: holding your thumb/finger in the spark plug hole and feeling when compression stops; you can 'find' TDC sticking a pencil/screwdriver/whatever in the spark plug hole and observing the point where it stops moving; you can use a bubble as described. Depending on what you are trying to do, any of those methods can work perfectly well.

Yes, you can misread a degree wheel or do the math badly but it's about as basic as math gets...determining 1/2 of a number. The biggest IN-accuracy issue using a piston stop/degree wheel involves the size of the wheel and the diameter of the pointer. If you print out a 4 1/2" 'degree wheel' from the internet and adhere it to a CD - which seems to be a fairly common recommendation - and use a piece of 12 Gauge Romex copper ground wire as your pointer, you have very closely-spaced indices and a pointer that will probably cover 4 degrees! Heck, it's probably LESS accurate than watching the pencil move up and down! :) OTOH, a 12" Moroso wheel with a sharp pointer will be dead-nuts accurate.

I am NOT saying that other methods don't work but on an accuracy scale, the degree wheel/piston stop is the most accurate. Yes, I admit that assumes it's a decent sized wheel/pointer and the operator knows how to do it. ;)
Click to expand...

Racing Yamaha 2-strokes, TDs, TRs and TZs where ignition timing is far more critical, a dial indicator with a spark plug hole screw in adapter (sold by Yamaha for the purpose) is all we needed to find TDC accurately enough. Just saying.
 
To be clear, I totally agree that most of the time, there is no need for degree wheels to make changes/settings. To me it's a one-time engine-building thing or a cam-timing thing if some specific cam requirements are involved.

I think it comes up here regularly because of the common "knowledge" that the timing scale on the Norton is not as accurate as it could be. Whether this is due to the slight shifting of the outer timing cover that can occur during installation, the accuracy of the the alternator rotor mark/the accuracy of the crankshaft/rotor woodruff key.

When I checked my scale/rotor mark with a degree wheel years ago, it was less than a degree off. But many folks have found them to be several degrees off so clearly there was a good bit of "slop" involved at the factory. When I installed the Alton E-start in '12, their rotor at the time did not have a timing mark (the current one does, I'm told). So I had to again break out the degree wheel to determine where on the rotor to inscribe a mark.
 
montelatici said:
Racing Yamaha 2-strokes, TDs, TRs and TZs where ignition timing is far more critical, a dial indicator with a spark plug hole screw in adapter (sold by Yamaha for the purpose) is all we needed to find TDC accurately enough. Just saying.
Click to expand...

Dial mike is OK when the plug hole is vertical, but on a Commando, it is on an angle. The rod in the lower part of the adaptor tends to stick.
 
Ignition Timing Setup Boyer
Ignition Timing Setup Boyer
Ignition Timing Setup Boyer
Ignition Timing Setup Boyer
After getting my new degree scale and tool to check the settings I had to post these pictures which lead me into doubts of any accuracy of more than one component.
Having set up TDC I was curious of the reading on my present gauge which gave me laugh cramps to the detrimental effect of me falling of my stool in the garage.
Having returned after TDLC I thought I would pull the rotor to find if it had been loose on its centre, fair enough it was loose on the rotor key and I don't like the look of the rotor so a new rotor and key must be bought.
I would appreciate other people's views and what they would do.
Somehow I must find a way of being able to use a strobe as using the sensitivity of the carbs is beyond me.
 
Well the rotor has been loose for a long time going by all the centre punch marks.
 
Somebody had fairly battered away at it demagnetising it in the process but as it looks they got it back to the right place, I think!
 
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