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Old 09-20-2019, 02:35 PM
paramehdic paramehdic is offline
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Default Rebuilding Childhood Go-Kart

Have go kart that I purchased ~20 years ago that I sold to my uncle and have since purchased back to use and now have my kids use it.

It has a centrifugal clutch however looking to switch it up to TQ.

Currently utilizing jack shaft
Clutch 10/12 (not sure on # on teeth) to 30t then 10/12 (again not sure) to 30t on axle.

Engine is GX240.

Current gearing seems fine just want to ensure if/when I switch to TQ it still remains in a usable state. Reading through all the gearing ratio posts I see more lost then when I started. Tires are 15", using #40 chain.

I also will need to redo the throttle control, currently a pedal bolted to side of frame and use brake lever type cable to pull throttle on engine / have spring on engine to return to idle. Find we always go through the cables as they stretch.

Any suggestions in regards to current gearing/switching to TQ/throttle control would be great! Oh and when I had it there were no brakes so need to setup that as well (it originally did have brakes but it was metal pads that pushed into the tire which bent badly during a crash many years ago and thus were removed)
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Old 09-20-2019, 08:07 PM
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Pictures might help... Go advanced the scroll down and it shows manage attachments you can add pics there.
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Old 09-20-2019, 11:02 PM
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Old 09-21-2019, 05:47 AM
paramehdic paramehdic is offline
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Pictures as requested.
Attached Thumbnails
gokart 2.jpg   gokart.jpg  

gokart3.jpg   gokart4.jpg  

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Old 09-21-2019, 08:27 AM
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with #40 chain it's likely a ten tooth clutch..
but you need to count the teeth I'm afraid

Since it's either 6.25:1 overall chain ratio or 9:1 ,,,,or maybe in between (7.5:1)
and if you want to maintain that ratio we can't calculate what axle sprocket would be needed ...
a GX240 (8hp) is right at the limit of what a series 30 TC can handle,
so you can still safely use it for the engine,
but you might also want to consider a series 40 already
say for a heavy two seater kart, with some more agressive riders... a bit beefier belt wouldn't hurt
And that again affects which sprocket size you want for the axle.

I think we talk about if a 52 or a 60 tooth axle sprocket will be needed in the end.
maybe even bigger.
Sorry but ideally just count the two smaller sprockets and let us know,
I think it's fairly safe to derive from that

bike brake cable is the goto solution for gokart throttle cables.
I'm not sure why you have to replace yours so often...
it stretches? well non prestretched steel cable does that of course,
but it needs to be adjusted (taking out the slack by shortening the effective length)
not replaced.

Also: you need to install new brakes... really
a simple disc kit off ebay a drum brake.. or back to scrub brakes as you had them.

running without any brakes is not a good idea, especially not with kids in the seat.
So please add brakes!

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  #6  
Old 09-21-2019, 08:37 AM
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Disc brake is in place just needs connected. Ill count teeth today and was think 40 series since its at the limit of 30 series.
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Old 09-27-2019, 10:11 AM
paramehdic paramehdic is offline
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Starting taking things apart today

Clutch is 10 tooth, jack shaft is 12 tooth

So 10 tooth > 30 tooth > 12 tooth > 30 tooth.

Think Ill stick with JS setup for now until things are going, any suggestions if I should change the sprockets or if the current gearing is good?
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