I have a kart that i am working on and i have a 8 hp briggs. I was wondering what would be good gearing for it. the tires are the small tires that are around 10" tall and i can get a clutch for it for real cheap so i was hoping to be able to use it. the clutch is 14 tooth (i can get it for $20) and i was hoping someone could help me with what size of sprocket for the single drive wheel. I used the search function but didn't find anything that could help me. Thanks for the help.
Good gearing for gokart with a 8hp motor
- Thread starter dustinp
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Generally, a 6:1 ratio is the go to... but that would mean that you'd need an 84T at your axle. That's too big for 10” tires. Your 8HP may be able to handle it, but sprockets are fairly cheap. I'd just put a smaller one on the PTO, so you don't have to go as big on the axle. You could also use a jackshaft.
Again, the "golden" ratio seems to be right around 6:1. A decent balance of torque and speed.
Again, the "golden" ratio seems to be right around 6:1. A decent balance of torque and speed.
I wouldn't get the 14T clutch. It would just mean that you have to get a huge axle sprocket or use a jackshaft. I would get a 12T or 10T sprocket and then a 72 or 60T axle sprocket
Then, you're in the right place
There are very many friendly, helpful, knowledgeable folks willing to help :thumbup:I don't know a whole heck of a lot about karts either, but if you're mechanically inclined, have decent tools and some common sense, that's all you'll need. The internet is a wonderful resource! I'm building up a mini bike currently, and before I started, I knew jack squat specific to this stuff. So far, I don't think I've done anything stupid... but only riding it for a length of time will tell for sure
OzFab
Well-known member
Being an 8hp, it's possible it has a 1" shaft, hence the larger clutch...
Since you have 10" tyres, I'm guessing it's a small, lightweight kart which means you can get away with slightly higher gearing but, it's still gonna be a squeeze finding an axle sprocket big enough to suit the necessary gearing yet small enough to suit the tyres
ok thanks for the help guys, i think i am going to do a jackshaft since i have the axle and bearing already, just need to get a couple small sprockets.
I also have another question, i have a nother kart and it is a smaller one and the wheels i have for it have a 5/8" hub and i am wanting to do a live axle with it and the only 5/8" sprocket hub i can find is this http://www.mfgsupply.com/gomini/gominisprockets/gominisprocketshubs/az2037.html. the problem is that i cant find a sprocket with this bolt pattern.
thanks
I also have another question, i have a nother kart and it is a smaller one and the wheels i have for it have a 5/8" hub and i am wanting to do a live axle with it and the only 5/8" sprocket hub i can find is this http://www.mfgsupply.com/gomini/gominisprockets/gominisprocketshubs/az2037.html. the problem is that i cant find a sprocket with this bolt pattern.
thanks
OzFab
Well-known member
Wait, are you saying you want to use a 5/8" live axle?
OzFab
Well-known member
Just a LOT A BIT! An axle should be 1" minimum! The axle on my kart is double that diameter...
firemanjim
Just kartin' around....
Where did you get a 2" axle? I must have been away from karts longer than I thought....
Dustin, them wheels are for the front spindles,and or, the dead axle (1wheel peel). I live axle hub doesnt have bearings in it (if u dont know) ,it has a hole with a key way cut in it, or is the "clamp" on type... Do the wheels youre reffering to all have bearings?
metric 50mm axles are really common on race karts...
well around here that is
'sid
well around here that is
'sid
firemanjim
Just kartin' around....
metric 50mm axles are really common on race karts...
well around here that is
'sid
Most people over here, have NO IDEA what 50mm is equivalent to.....
Thats foriegn to them.... all our stuff is in inches..... 
Tony could have meant double the 5/8" that the OP was talking about
*shrugs*
Most people over here, have NO IDEA what 50mm is equivalent to.....
So you're saying most people around there have no idea who Jimmy Carter is most famous for?
that's a pitty
well 1inch = 2.54 cm = 25.4 mm (hooray to the metric system)
1.25 " axle.. thatsounds like an odd size.. 30mm on the other hand is also quite common around here (for smaller karts)
But we'll never know... Tooonyyy?
'sid
You can say that again
The metric system is far superior. It's so simple. I wish my country would just switch.
Where I work, a lot of the equipment originated in the UK, France, or Italy... combined with all of the machines we make ourselves. Then, sometimes the metric machines are modified, but with imperial measurements, in addition to having some whitworth bits as well.
Keeps you on your toes!!
Where I work, a lot of the equipment originated in the UK, France, or Italy... combined with all of the machines we make ourselves. Then, sometimes the metric machines are modified, but with imperial measurements, in addition to having some whitworth bits as well.
Keeps you on your toes!!
OzFab
Well-known member
I'm not gonna bother multiquoting, there's too many so:
Although 50mm axles are more common than anything else these days, I was referring to double 5/8", being 1.25" or 31.75mm.
My axle is actually 30mm but I said double for simplicity reasons (as explained above
)
So, Paul & 'sid, you were both correct in your own way...
For the record, 2" = 50.8mm so 50mm would be around 1 31/32"
Metric is soooo much easier to read & use...
Although 50mm axles are more common than anything else these days, I was referring to double 5/8", being 1.25" or 31.75mm.
My axle is actually 30mm but I said double for simplicity reasons (as explained above
)So, Paul & 'sid, you were both correct in your own way...
For the record, 2" = 50.8mm so 50mm would be around 1 31/32"
Metric is soooo much easier to read & use...
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