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#Post#: 13601--------------------------------------------------
I need help with my sprockets!!!
By: uncantim Date: August 1, 2025, 5:10 am
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Ok team, I need your help again.
I am going up a chain size from No35 to 420. The No35 is, in my
opinion, too flexible and stretches and jumps under heavy
acceleration. Going for a 420 gives me more options for
gearing…or so I thought. I intended to have a 70-tooth main
sprocket and a 10-tooth (or less) on the output shaft of the
torque converter but the torque converter sprocket doesn’t fit.
This is where I need your help…
Can you guys help me to find a 10-tooth, 420 sprocket for the
torque converter? The output shaft is 16mm with a 5mm keyway.
The sprocket I already have is 16mm wide.
Or
Suggest where I can get a new torque converter with a 420 output
sprocket?
The pictures are of the No35 sprocket off the torque converter I
already have. It’s 16mm bore, 5mm keyway and 16mm wide.
Being a Yorkshireman, I don’t like spending money, so I’d rather
find a sprocket to fit than buy a whole new torque converter.
Any help is greatly appreciated
#Post#: 13602--------------------------------------------------
Re: I need help with my sprockets!!!
By: StefanN Date: August 1, 2025, 5:28 am
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The sprocket bore is normally 5/8" I think. I found some on
eBay - I'll see if I can find them again and post the link
#Post#: 13603--------------------------------------------------
Re: I need help with my sprockets!!!
By: jon.pearce Date: August 1, 2025, 5:29 am
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Go 219 pitch....modern kart chains are much higher quality than
35 pitch.
15T - 98 will give you a good 6.5:1 ratio
#Post#: 13604--------------------------------------------------
Re: I need help with my sprockets!!!
By: jay pratt Date: August 1, 2025, 6:40 am
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I have at least 1 brand new 5/8 420 chain 10 tooth sprocket from
a vevor kit. I too thought they were all 5/8
#Post#: 13605--------------------------------------------------
Re: I need help with my sprockets!!!
By: Jimr1999 Date: August 1, 2025, 7:09 am
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I have a vevor 10 tooth Tim, I bought a 9 tooth and that was a
fit for a genuine comet but I got it to fit with a round bastard
file. And some patience. The keyway was still plenty as it
didn't need much off. If you need the 10 tooth, I will donate
for beer
JimR
#Post#: 13606--------------------------------------------------
Re: I need help with my sprockets!!!
By: EARWIG Date: August 1, 2025, 11:52 am
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my torque converter came with a 10T 428 sprocket (correct pitch
- wrong thickness ) - 16mm bore.
I just bough t a 10T 420 16mm bore off eBay. just under £10.
Would send you the link - if I knew how !!!!
#Post#: 13607--------------------------------------------------
Re: I need help with my sprockets!!!
By: NewbieNick Date: August 1, 2025, 12:30 pm
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Hi Tim , my MG has 420 chain 9 tooth drive 60 tooth axle giving
66.1 .the drive sprocket took quite a long time to ream to fit.
The Wasp has 219 chain & sprockets. The 15 tooth drive sprocket
from Gemini is quite expensive & needed reaming to fit, however
219 sprockets are really cheap & readily available. I bought 5
unused sprocket’s for £30.00 on eBay. Big advantage with 219
chain is they don’t need a joiner link. You just need a special
tool to press links together.
Hope this helps cheers Nick
#Post#: 13608--------------------------------------------------
Re: I need help with my sprockets!!!
By: uncantim Date: August 2, 2025, 2:05 am
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Fellas, your input is amazing, thank you so much.
I'm sorted for now thanks to Jim but everybody's advice is
invaluable for the next one.
Thanks once again.
T
#Post#: 13610--------------------------------------------------
Re: I need help with my sprockets!!!
By: RhysN Date: August 3, 2025, 9:13 am
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One potential downside to 420 chain is that it is so much wider
that clearance on the TAV becomes (or can become) marginal. Also
when buying sprockets be aware that 428 sprockets and 420 chain
are not compatible.
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