Zorst camshaft repair?

Information relating to the Matchless G3 or AJS Model 16 350cc Heavyweight
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Andy G
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Location: Aberdeenshire UK

Zorst camshaft repair?

Post by Andy G »

Due to some heavy handedness by CO :oops:
I need to replace or repair the threaded end of the exhaust cam assembly that secures the magneto drive gear
Now theoretically I could drill and tap for a bolt to secure the gear, but it appears that the shaft may be keyed into the gear/cam assembly.
Is it? Have I got the faintest chance of pressing it out? If so, I might be able to get a new shaft made..
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Last edited by Andy G on Mon Dec 05, 2022 6:51 am, edited 1 time in total.
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ajscomboman
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Re: Zorst camshaft repair?

Post by ajscomboman »

How about asking spares if 010829 camshaft spindle long, is suitable, there is no picture but if they load one onto the system then all could see. Failing that then if you can find a used but not as good cam then yes you can press out the offending item.
Andy51
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Re: Zorst camshaft repair?

Post by Andy51 »

I have pressed shafts in without problems, to create a good whole cam from 2 others, one with a good cam and the other with a good shaft. Used a 10 ton press in a garage workshop, measured shaft protrusion and was careful to meet required dimension. Good shafts seem to be easier to find than the cams themselves, which are often badly rust pitted. As far as I know, same shaft is used until alternator models, only cams varied. Cheers, Andy
Andy G
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Location: Aberdeenshire UK

Re: Zorst camshaft repair?

Post by Andy G »

Thanks chaps, I'll see if I can confirm dimensions of 010829, and if it's good, I'll look around for a big press!
I've posted a wanted add also, just in case.
Will update.
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Andy G
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Posts: 358
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Location: Aberdeenshire UK

Re: Zorst camshaft repair?

Post by Andy G »

As if by magic a picture has appeared..was some kind soul listening? No dimensions or suggested application tho, so I have emailed and asked for more information.

In the meantime I borrowed a complete exhaust cam from a bike that is further down the "get around to it " list. Unlike the broken one which is marked with 1 and 2 dots, the borrowed one has 1 2 3 suggesting a later version and matching the 1 2 3 on the inlet. All are marked H for high lift.

I set up using a timing wheel as the standard dot settings of inlet 3 (350) and exh 2 (350/500) were hopelessly off.
The best results ended up being 3 and 1, which
was very concerning until I stumbled on this:

g80csp11 wrote:
Note........If a keyway is not visible in the cam wheel use No.1 mark for the
exhaust-cam setting, before 1956-57

Now there's a confidence booster!

I'll continue to pursue repair to the cam I broke, but I suspect I was already starting with a mixed bag, and if it eventually runs then I'll be happy!
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Andy G
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Location: Aberdeenshire UK

Re: Zorst camshaft repair?

Post by Andy G »

For further information on the shaft 010829, while I still can't find it in my parts list, I did find it on a cut away engine drawing in archives.jampot.dk. (eternally grateful for this resource)
It appears to be same for 350/500 singles and regardless of year.
I'll order one with fingers crossed
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