1967 G15: sprocket and chain

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Hi.
My 1967 G15, in restoration, has all missing the primary system.
It is not a great problem because i have a lot of parts from my previous P11s and N15 rebuilt.
But mine N15/P111s have 21 theet sprocket with 68 chain links.
Roy Bacon book says G15 has 22/23 primary sprocket theet.
Please, can i mount 21/68 but, in case of 22/23, how many should be the links?.
Thank you.
Piero
 

N0rt0nelectr@

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Piero,
My parts book for the G15's / N15's only lists the 68 link primary chain. It lists 21 toothed engine sprocket as standard with 22t std on the G15Mk2 and G15CSR. I would guess that there is enough adjustment to use either. The parts book lists 17 to 21t engine sprockets as an alternative to the ones fitted from the factory. Hope this is of some help.
John in Texas
 
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Piero,
My parts book for the G15's / N15's only lists the 68 link primary chain. It lists 21 toothed engine sprocket as standard with 22t std on the G15Mk2 and G15CSR. I would guess that there is enough adjustment to use either. The parts book lists 17 to 21t engine sprockets as an alternative to the ones fitted from the factory. Hope this is of some help.
John in Texas
HiJohn.
Thank you.
Piero
 
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Yes, The engine sprocket on the CS is 21 tooth. The sprocket on the clutch basket doesn't change - 42 tooth. The final drive sprocket is normally 16 to 19 tooth on the CS, and the rear sprocket doesn't change - 42 tooth.

68 roller primary chain and 98 to 99 roller final drive chain, dependent on your front final drive sprocket
 
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Piero,
My parts book for the G15's / N15's only lists the 68 link primary chain. It lists 21 toothed engine sprocket as standard with 22t std on the G15Mk2 and G15CSR. I would guess that there is enough adjustment to use either. The parts book lists 17 to 21t engine sprockets as an alternative to the ones fitted from the factory. Hope this is of some help.
John in Texas
Hi.
What bhanges with 22 t instead of 21?.
Thanks
Piero
 
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21/42 sprocket combination increases engine revs by almost 5% versus 22/42 sprocket combination.

It doesn't sound like much, but combined with a 16 tooth final drive sprocket, it gives the CS a noticeable improvement in acceleration.
 
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