Timing Light Issue

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On one of the bikes, can't remember which one probably one with magneto, feeding the ignition timing light from a separate battery.
It didn't work. turned the pickup clamp around and it worked. So the pickup was sensitive to the direction of current in the HT lead.
One of those fancy modern lights where you adjust strobe flash to TDC mark and get degrees on a digital display.
 
Mike40M said:
One of those fancy modern lights where you adjust strobe flash to TDC mark and get degrees on a digital display.
Click to expand...

Any timing light with an advance-retard adjustment control needs to be set to 0 degrees for a Commando (or other ignition that has a full advance timing mark/setting).
 
Ron Hulton said:
Just a further update to my original question and results of further checks .. Yesterday i tried a new to me but very old timing light and got the same results . No matter what configuration of hook up to the plug wires i tried , i could get no signal . From there i hooked up to the trigger wire from the tri spark and all worked as expected . As i stated in my original post , my MKIII works very well , although i have for years seemed to think it was a little rattly from the top end .......... valve adjustment or almost like a timing issue ??

Warmed the bike up and brought it up to 3000 rpm .. ( an rpm that kept the bike from skating across the garage floor ) .. Best estimate would be somewhere about 50 deg before TDC.. This can't be correct ..it works too well . Loosened off the tri spark and brought it back until the red light came on AND at 28 deg . Same thing ............ Started set up from the beginning , set 28 deg , centered tri spark and marked position , reinstalled magnet and reinstalled tri spark.. Minor adjustment after starting gave me 28 Deg at 3500 .. Test ride showed a completely different much smoother response and my upper end rattle is gone .. Just one for the books i guess .. ;)
Click to expand...
""""From there i hooked up to the trigger wire from the tri spark and all worked as expected"""" .

If you are getting your timing light trigger from the primary side of the coils, your timing light flash will be "early" by the amount of dwell degrees of the electronics. The electronics energize the coil primary (like points closed) then switch off (points open) then the plugs fire. The "time", in crank degrees, that the coils are energized is the dwell. The spark event occurs when the coil primary current goes to zero. To be accurate, the timing light must get the flash signal from the secondary side of the coils. This would explain the orginal higher BTDC timing. IMHO your timing is now retarded.
Cheers
 
Tornado said:
A good tip for keeping bike in one place while reving to 3-4k on CS is to place some foam pads/yoga matts etc beneath the feet. I find it quite effective.
Click to expand...
I use a wheel chock on the front wheel - mine is part of my lift bench. FWIW
 
Steve W. said:
""""From there i hooked up to the trigger wire from the tri spark and all worked as expected"""" .

If you are getting your timing light trigger from the primary side of the coils, your timing light flash will be "early" by the amount of dwell degrees of the electronics. The electronics energize the coil primary (like points closed) then switch off (points open) then the plugs fire. The "time", in crank degrees, that the coils are energized is the dwell. The spark event occurs when the coil primary current goes to zero. To be accurate, the timing light must get the flash signal from the secondary side of the coils. This would explain the orginal higher BTDC timing. IMHO your timing is now retarded.
Cheers
Click to expand...
Maybe try a cheap plug wire just for setting your timing?
 
Derek Wilson said:
I use a wheel chock on the front wheel - mine is part of my lift bench. FWIW
Click to expand...
I tried a wheel chock once, but found impossible to reach the throttle grip while head down near primary cover timing hole. Can just reach if handle bars turned full right, can't do that in chock.
 
To keep the bike in one place while on the center stand, I use a square of truck mudflap. Makes it easier to roll off the stand rather than skidding on the finished concrete.
 
Thomasa said:
To keep the bike in one place while on the center stand, I use a square of truck mudflap. Makes it easier to roll off the stand rather than skidding on the finished concrete.
Click to expand...
I find thick anti-fatigue or yoga mat material works a treat...and I don't need to pilfer a mudflap off a nearby truck ;-)
 
Tornado said:
I tried a wheel chock once, but found impossible to reach the throttle grip while head down near primary cover timing hole. Can just reach if handle bars turned full right, can't do that in chock.
Click to expand...
I use the damper screw on the twist grip to lock the throttle
 
solo timing set up

IMG_3940.jpg
 
For those of you who still haven't found a timing light that works on your Norton , let me inform you that a Sun Inductive Timing Light .......Model CP 7501 works just as one would expect . I recently became the new owner of this light and it works perfectly on both sides . You do need to flip the clamp over when doing one side .. There were a few on E Bay but shipping to Ontario Canada from California was pretty dear . Fortunately my best friend just happened to find this one while on a bike trip in the USA ..
 
I have used this one since 2015: Amazon product ASIN B00063WM1Q

Works on every engine I've timed. Not cheap but I like only having to deal with one wire. Haven't noticed the need to turn it over on dual coils but might have just been lucky and got it right the first time.
 
I prefer one powered by 12V - seems to give a brighter light.
This one has been good for me:
automotivesuperstore.com.au

Hella Timing Light 7023

Shop for Hella Belt & Timing Tools and save with Automotive Superstore! Get the best price, fast shipping and quality parts to your door.
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