Timing lever direction convention

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Timing lever direction convention

Postby Antoni » Tue Aug 13, 2019 6:40 am

I'm new to the game. My 1953 G3LS had its front brake torque bar on the right side and therefore in compression and therefore dangerous. It had a timing lever installed on the wrong side of the 'bars. Both errors corrected. Pull the timing lever back most of the way and you don't end up with painful neck muscles on attemting a start. It's retarded pulled back and advanced when pushed. The mag has its control cable on the forward side

My AJ Bitsa has a 1953 G80 engine with the same mag set-up at the front of the engine but has its control cable coming off the mag on the other side - the cylinder side. As a result the timing lever works in the opposite sense.

Is there a convention? Is it just another case of "If it can be wrongly asembled it will be" ?

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Re: Timing lever direction convention

Postby MalcW » Tue Aug 13, 2019 8:26 am

Antoni wrote:
Is there a convention? Is it just another case of "If it can be wrongly asembled it will be" ?


I don't think there was ever a convention, just different designs. It's more a case of "if you can use it wrongly, someone will".

Malc

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Re: Timing lever direction convention

Postby SPRIDDLER » Tue Aug 13, 2019 8:49 am

Antoni wrote:I'm new to the game. My 1953 G3LS ...........The mag has its control cable on the forward side

Bikes made up to Aug 31st 1953 were '53 models. After that it would be a '54 model.
My (ex-Plumstead May '54 G3LS) with an N1 mag has the A/R cable entering on the cylinder side.
I believe mine - 2 previous owners (shipped new to the Rhodesian Police then to previous owner living 10 miles from me) has its original mag.
No idea why they should differ. Possibly a hangover from earlier Matchless singles that had the mag located behind the cylinder?
'Groily' is the mag guru who may have the answer...........if there is one :?:
I poke badgers with spoons.

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Re: Timing lever direction convention

Postby GOLDSTAR » Tue Aug 13, 2019 12:07 pm

G80cs comp mag, slack wire advance, DB32 Goldstar tight wire advance, confusing so changed it to slack wire advance[,damn lot of trouble to do]
following these two I purchased an Ariel W/ng tight wire advance :headbang: it can damn well stay as such, now the Velocette a sophisticated and civilised machine, slack wire advance, ah thats better :beer: ! kind regards

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Re: Timing lever direction convention

Postby Groily » Wed Aug 14, 2019 10:08 am

Not sure if there's any real convention here, but slack and tight wire advance, for clockwise and anti-clockwise rotation from drive end are all options! Personally,like Goldstar, I prefer slack advance if cable routing permits, as the default position if the lever slips at the bars is full advance. But horses for courses. Some makers seemed to adopt one, others t'other.
Some mags will have had their cb end housings changed over the years, to alter the input side of the cable.
Some mags will have had their direction of rotation changed too probably.
Some have even had their HT pick-up moved across from one side to the other and the original blanked off - but that a least is an obvious mod!
Only the Parts Lists can really tell us what went originally on what. And even then, it needs the ID tag not to have been changed over time to say something different from original. And the Parts Lists are an excruciating read, as those of us who pour over them often can attest!
The good news though, is that almost anything can be made to work fine on almost anything, either direction of rotation, cable routing permitting.

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Re: Timing lever direction convention

Postby Antoni » Wed Aug 14, 2019 4:46 pm

Clear info given.
There is no convention. There's only manufacturer's convenience when making a particular motorcycle model.
Thanks each.

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Re: Timing lever direction convention

Postby JimFitz » Wed Aug 14, 2019 8:34 pm

I have a number of old British bikes and they are all manual A/R and I can never remember which way round advance and retard is. Having had a few painful kick backs I have now painted a small red dot on each A/R lever showing the direction of advance.
Simples.... no more limping around :D

Jim
Too old to Rock and Roll but too young to die.

1952 G80 rigid, 1960 G12 DL / Watsonian Monza, 1954 G80S.

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