Ignition Timing

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
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spookefoote1956
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Ignition Timing

Post by spookefoote1956 »

Hello again everyone. I'm doing some work on "The Beast" which has a 56 500cc engine. I'll be re-checking the ignition timing, which is Thorspark not points. This time I'm going to use a magnetic inclinometer as shown below instead of an old spoke or a timing disc. Find TDC (Fully advanced), zero the device then roll back to 39 degrees before TDC then set the trigger on the Thorspark.

Has anyone else had experience of using such a device and how good / reliable did you find it?

Cheers, Chris
Magnetic Inc (2).jpg
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Andy G
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Re: Ignition Timing

Post by Andy G »

spookefoote1956 wrote: Sat Apr 02, 2022 8:12 pm Find TDC (Fully advanced), zero the device then roll back to 39 degrees before TDC then set the trigger on the Thorspark.
Fascinating widget of which I have no experience, but presumably still beneficial to roll back further, then forward to 39 deg to take up lash?
Or does it somehow not matter when running thorspark?
Bombling contentedly around rural Aberdeenshire
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spookefoote1956
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Re: Ignition Timing

Post by spookefoote1956 »

The Thorspark trigger just replaces the points which activates the coil at the required time. I just want to give it a go instead of faffing about with a spoke or disc with a bit of wire as a pointer.
Hail Joe Lucas ............ Prince of Darkness!
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dave16mct
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Re: Ignition Timing

Post by dave16mct »

Do you attatch it to the camshaft sprocket with it's magnetic back? Seems like a good idea. You'll still have to wedge the auto advance open.
Dave.
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spookefoote1956
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Re: Ignition Timing

Post by spookefoote1956 »

Apparently you make an L shaped bracket and attach that to the sprocket with a neodymium magnet.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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spookefoote1956
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Re: Ignition Timing

Post by spookefoote1956 »

My new toy arrived today. I'm looking forward to using it to time "The Beast"
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Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
Allen_F
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Re: Ignition Timing

Post by Allen_F »

I put Thorspark on my 53 enfield. works great. Interested in the digital inclinometer. pics paint a 1000 words. keep it up.
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spookefoote1956
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Re: Ignition Timing

Post by spookefoote1956 »

Will do Allen. I've got to re-wire "The Beast" first but rest assured I will post loads of pics.
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
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