Timing Light Issue

I believe this was briefly discussed by a few back in 2009 but reason was never answered .

1975 MKIII Works great . Taylor 8mm spiro Pro plug wires . Non resistor caps . NGK BPR7ES plugs .. Crane coil from CNW .. Tri-spark EI new in 2021.

I have not checked the timing for years so i thought that it would be nice just to see where it is at .. My friend came over with his timing light and to my displeasure , it would not work . I supplied power from a separate battery but it will not pick up the signal pulse .. Hooked it up to my lawn mower ( with points ) and it works fine . Interesting enough , it will not work on his 74 Commando ( same coil .. same tri-spark .. 5K caps and non resistor plugs ) yet it will work on his old 1950 's bike .

Not sure the brand name or age of the timing light . Works on everything else but a Norton ..

Cheers

I run solid copper wires, no resistor caps, resistor in plug and have 2 strobe lamps and both work with the one capable of running off a separate battery working off the bikes own battery. The battery powered one is a Gunson's Timestrobe.

Amazon product ASIN B0012M9KGA

Your timing light (assuming it's triggered by an induction clamp over the plug lead) will struggle with your Spiro Pro leads which are heavily suppressed to prevent interference (your lack of pulse proves they are doing their job)

Furthermore, timing lights tend not to like dual output coils.
You will have to reverse the clamp depending on the side, but even then, the pulse will be weak.

Ron Hulton said:

I believe this was briefly discussed by a few back in 2009 but reason was never answered .

1975 MKIII Works great . Taylor 8mm spiro Pro plug wires . Non resistor caps . NGK BPR7ES plugs .. Crane coil from CNW .. Tri-spark EI new in 2021.

I have not checked the timing for years so i thought that it would be nice just to see where it is at .. My friend came over with his timing light and to my displeasure , it would not work . I supplied power from a separate battery but it will not pick up the signal pulse .. Hooked it up to my lawn mower ( with points ) and it works fine . Interesting enough , it will not work on his 74 Commando ( same coil .. same tri-spark .. 5K caps and non resistor plugs ) yet it will work on his old 1950 's bike .

Not sure the brand name or age of the timing light . Works on everything else but a Norton ..

Click to expand...

I have exactly the same problem but perhaps gforce has enlightened me

gforce said:

Furthermore, timing lights tend not to like dual output coils.
You will have to reverse the clamp depending on the side,

Click to expand...

I was also just going to say:
Did you try the pickup on both plug wires as one dual coil pulse is positive and the other, negative so the strobe pickup (normally arrowed for connection) might only work on one of the two unless reversed?

Appreciate the views .. At least i have something to try .

I've got a vintage timing gun with a springy thing to attached between the spark plug and inside the of the cap. No inductive pickup. Works a treat.
My modern digital gun with inductive pickup also seems to work fine on my Norton but bike does not have surpressed cables.
The digi gun has rpm readout and can advance the gun's flash by a preset amount which is useful when needing to set ign to a value not on the timing scale.

Taylor Spiro pro leads are completely different to suppression leads , I have made up 3 or 4 V8 sets in Taylor Spiro pro 10mm lots of insulation , ice coil, I have two Sun pro timing lights, one a dial back they both work on those leads , inductive clamp , worked on my 750 as well , don't know what the lead type is. Could you try one of the cheap types that is powered by the plug lead ? Cheers

@Shelby-Right I have no wish to argue - I only shared what I have found on my own bikes.

This line on their site is what gave me the idea to try a different plug lead:
"Superior RFI/EMI suppression for application is with CD or electronic ignitions, on board computers, stereos or pit radios"


When I time my bikes (which use the standard Colorado Norton Works setup of the Taylor 8mm Spiro Pro plug wires and Crane dual output single coil), I use an old plug lead as my timing light doesn't work otherwise.
I just swap it back when I'm done.

To be clear, I am not being negative about the Taylor leads - they seem fine otherwise.


I'd be interested to hear more from @Tornado about the a "springy thing to attached between the spark plug and inside the of the cap" - it sounds like a good, simple solution to me.

I'd be interested to hear more from @Tornado about the a "springy thing to attached between the spark plug and inside the of the cap" - it sounds like a good, simple solution to me.
[/QUOTE]

Instead of an inductive clamp, the trigger lead connects to mid point of a 2" coil spring. One end of spring has a slight flare so it easily pushes onto spark plug terminal. Other end is more tightly wound so it fits inside the plug wire cap. Basically just becomes a non insulated conductor 'tween cap and plug, with a gun's trigger lead clamped/crimped to it. You could rig up a similar exposed conductor on any bike, then just clamp your fancy-folk inductive pickup gizmo on to that for your timing checks.

G-force , you seemed to read that in an angry way, sorry , this was my experience with spiro's ,and all inductive the clamps won't close properly on the 10mm leads ,but my T/lights work great, as i said i did have a high output coil , i think the HT lead change , or the metal spring may do the trick, sounds great .Cheers

Yes I think inductive pick up clamps need to fully close in order to work. Mine has a warning sticker about not dropping it to avoid damaging the plastic clamp, preventing proper closing.
Having a thicker than standard cable could be an issue with some clamps.

Interesting . Dereck Wilson and myself put the MK 111 up on the hoist to try ign. timing at 5000 R.P.M. and got no reading . Stumped.

Have you tried that timing light on your car ? .

Sometimes pulling the plug wire back from the spark plug end to create a small air gap for the spark to jump will create enough signal for the induction light to work.

Creating an air gap between the plug wire and spark plug will cause a rise in the voltage output of the ignition coil. [at least in a good coil] FYI, an old mechanics' trick to clear a fouled spark plug is to do just that, create a gap. Then ride the bike at a steady 40 MPH for at least 5 miles once the plug starts firing again. Those 5 miles allow the porcelain of the spark plug to heat up to operating temperature [approx. 900 F]. Once hot, the spark plug will clean itself.

A variant of the old "non inductive" style timing light is linked below. The red and blue clamps go to the battery. The two black leads go to the spark plug wire [coiled spring] and onto the spark plug [sheet metal tube end]

https://www.cx500forum.com/attachments/img_4695-jpg.14644/

The more common of these old timing lights only had 3 leads. Two went to the battery for power, the third had an alligator clip on the end. A tapered coil spring was included. This fit between the coil wires' end and the spark plug. The alligator clip was then attached to the spring.

Shelby-Right said:

Have you tried that timing light on your car ? .

Click to expand...

No. Never owned a car . 19 bikes later though.

My timing light fits in the circuit between the coil and the plug. It does not have a separate power supply. It works, but not very well. One thing I always very hard not to do, is disturb the rotor set-up on the Boyer. Once I have a timing set up, I tune to suit it. If I disturb it, I start checking the jetting. There is a balance between comp. ratio, ignition timing and jetting. It does not matter much within reason, where the timing is as long as you restore the balance. Advancing the timing or raising the comp, have the same effect as leaning off the jetting. That is probably most of the reason your bike goes faster , if you raise the comp - it is the same as leaning-off when you are jetted slightly too rich.

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 ..

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.