Magneto Timing Light

Paul W. · Jan 1, 2019

Has anyone used a magneto timing light? I was thinking back to my A&P school days and timing aircraft engines. They make a product for single magneto engines that tells you precisely when the points open and close without pulling the cover. Joe Hunt and others have products. I was looking at this product. Thoughts?

texasSlick · Jan 1, 2019

Dunno about JH magnetos, but a Lucas K2F will tell you when points open/close with a simple bulb & battery, or with a VOM. I tell you how to time a K2F here: https://www.accessnorton.com/NortonCommando/setting-up-and-timing-a-k2f-magneto.19685/

Slick

Paul W. · Jan 1, 2019

texasSlick said:
Dunno about JH magnetos, but a Lucas K2F will tell you when points open/close with a simple bulb & battery, or with a VOM. I tell you how to time a K2F here: https://www.accessnorton.com/NortonCommando/setting-up-and-timing-a-k2f-magneto.19685/

Slick

I have your post printed out in my garage. Very informative and a great many thanks!

Unfortunately, the JH I have does not let me use a VOM or light method. I could not get a change in readings with any of my meters, and I used four different Fluke’s. I also tried the battery and bulb method with no change of state. Light was aways on. I have to remove the cap and condenser to get the light method to work, which requires the removal and reinstallation of the points to get to the condenser wire terminal. Then I have to reverse the process when completed. This includes resetting point gap. As you can figure, it makes the process very tedious. A $50-60 investment would be worth it to me.

texasSlick · Jan 1, 2019

@PaulW

I suppose the JH works like the Lucas K2F, that is, an ohm meter across the points will indicate continuity with points open and closed due to the internal windings. In the case of the K2F, removing the center screw isolates the points from the internal windings, then allows the use of a bulb/battery or VOM.

From your description of the procedure to isolate the points, I would agree that a tool that senses point opening without all that hassel is worth its price. OTOH, once the magneto is set up and timed, you will not use that tool for a very long time!

Slick

ekkeneckepen · Jan 2, 2019

Paul W. said:
Has anyone used a magneto timing light? I was thinking back to my A&P school days and timing aircraft engines. They make a product for single magneto engines that tells you precisely when the points open and close without pulling the cover. Joe Hunt and others have products. I was looking at this product. Thoughts?

Hello Paul, what is the problem to open the Magneto Cover? If you want to adjust the magneto you must even open the cover - or not? For exact checking the point of opening and closing I measure the different current with an analog Ammeter.

marinatlas · Jan 2, 2019

Not the good answer for a Joe Hunt but :
http://www.themagnetoguys.co.uk/points-cap-cut-out

Bernhard · Jan 2, 2019

Bulb and battery will not work on K1f or K2F UNLESS you remove the centre bolt, - and hope that the points stay in place!!!!!

Paul W. · Jan 2, 2019

I went ahead and ordered it. Thanks to my sis for the Amazon gift card for Christmas.

jimj · Jan 3, 2019

Paul W. said:
I went ahead and ordered it. Thanks to my sis for the Amazon gift card for Christmas.

Bought one of these when I was setting the timing on a couple of old trials bikes. It really worked great, kicked myself for not buying one years ago. https://www.skygeek.com/action-air-22296-deluxe-single-magneto-synchronizer.htm

Paul W. · Jan 3, 2019

jimj said:
Bought one of these when I was setting the timing on a couple of old trials bikes. It really worked great, kicked myself for not buying one years ago. https://www.skygeek.com/action-air-22296-deluxe-single-magneto-synchronizer.htm

Thanks! That's exactly what I purchased and it will be here first part of next week. Since I found out my pistons are flat and should be at 28°, and not 32°, this will help me tremendously when I time it again. And, hopefully, this will get rid of the pinging that the engine has when it warms up. If not, I'll sell the whole lot after I switch to a Pazon ignition.

bad_friday · Jan 4, 2019

I have bought this http://www.themagnetoguys.co.uk/magneto-static-timing-light from Al Osborn because I trust Al. But never used it until now because my mechanic timed my K2F by the «Cigarette-Paper-Method».

Bernhard · Jan 4, 2019

As stated on their website;
Why can’t a simple battery and bulb be used to do the same job?
In a magneto ignition circuit the points, condenser and primary winding of the magneto armature are all in parallel. Current in a circuit will always flow via the easiest path. This will be through the points if they are closed, or through the primary winding if they are open. Either way, the bulb will stay on whether the points are open or not! Try it and see!
true......but as I stated earlier; Bulb and battery will not work on K1F or K2F UNLESS you remove the centre bolt, - and hope that the points stay in place.

Paul W. · Jan 4, 2019

Bernhard said:
As stated on their website;
Why can’t a simple battery and bulb be used to do the same job?
In a magneto ignition circuit the points, condenser and primary winding of the magneto armature are all in parallel. Current in a circuit will always flow via the easiest path. This will be through the points if they are closed, or through the primary winding if they are open. Either way, the bulb will stay on whether the points are open or not! Try it and see!
true......but as I stated earlier; Bulb and battery will not work on K1F or K2F UNLESS you remove the centre bolt, - and hope that the points stay in place.

I agree with just one correction they drilled into me as an electrical apprentice over twenty years ago. Current flows through ALL available paths.

Paul W. · Jan 4, 2019

bad_friday said:
I have bought this http://www.themagnetoguys.co.uk/magneto-static-timing-light from Al Osborn because I trust Al. But never used it until now because my mechanic timed my K2F by the «Cigarette-Paper-Method».

I looked at that one, but since I’m in the states, it was cheaper and quicker to get the other one. It should be here this morning.

desmo · Sep 1, 2019

why not just use the old cigarette rolling paper its good enough any discrepancy can be adjusted out at the points
opening them advances
closing retards

attach a degree disc to the drive end and fine tune cam ring by stoning with a fine rotary sanding drum
ive even made single cam rings into 50 degree operation for my old v twin enfield

jseng1 · Sep 6, 2019

I just use my regular automotive timing light on my JH mag. Its a little erratic with a few false flashes but you can still see the timing marks and check the accuracy of your "cigarette paper" timing.

Magneto Timing Light

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