Traction issue. Newbie needs help.

[ryanpeel]

I have a dead axle go-kart for my kids. The picture pretty much shows all. I am having trouble with it where the go-kart won't go and just sits there and spins the tires, turfing the yard or throwing gravel from my driveway. The engine runs great but it's like there's too much torque or something. I just put new knobby tires on the back, including the drive wheel.

I'm assuming I'm not the first one to have this problem. What can be done to prevent this tire spinning action from occurring upon startup. It's even an issue when driving too (doesn't take much gas/throttle and the drive wheel spins like crazy).

Please help if you can and thanks.

 

[thisismyusername]

I have a dead axle go-kart for my kids. The picture pretty much shows all. I am having trouble with it where the go-kart won't go and just sits there and spins the tires, turfing the yard or throwing gravel from my driveway. The engine runs great but it's like there's too much torque or something. I just put new knobby tires on the back, including the drive wheel.

I'm assuming I'm not the first one to have this problem. What can be done to prevent this tire spinning action from occurring upon startup. It's even an issue when driving too (doesn't take much gas/throttle and the drive wheel spins like crazy).

Please help if you can and thanks.

I would say its probably the gear ratio, if the kart is pretty much only torque than your not going to get much speed and its just going to have lots and lots of power. What is your gear ratio and what size are the tires?

 

[ryanpeel]

Here is what I know. Can you help me determine if the problem is the gear ratio?

The engine is a Tecumseh OHH50. I do now know anything more about the engine but I included a picture of the sticker on the engine.

The gear on the engine has 12 teeth. The gear on the axle/wheel has approximately 88 teeth (I counted what looked like 1/4 of the gear and multiplied that number by 4).

The tires are 145/70-6 from Tractor Supply.

 

[chancer]

Your gear ratio is the big gear divided by the little gear. A solid example is karts running 6:1 with 13" tall tires. for example 72 and 12 teeth. You have 7.33:1. (88/12) This is giving you more torque than you want. Causing excess tire spin. You can get taller rear tires or try a 72 tooth axle gear. Either way keep in mind this will increase the Top speed a little. How tall are the 145/70 tires?

 

[ryanpeel]

Thanks this is really helpful. I understand a bit better now. I measured the tires from bottom to top when sitting on the ground. Just about 14" tall. Where can you get a 72 tooth axle gear and/or different tires?

 

[chancer]

Shop around online, here is a long list.
http://www.diygokarts.com/vb/showthread.php?t=1180

 

[Poboy kartman]

Thanks this is really helpful. I understand a bit better now. I measured the tires from bottom to top when sitting on the ground. Just about 14" tall. Where can you get a 72 tooth axle gear and/or different tires?

Should be closer to 13..... probably WAY overinflated....which also contributes to wheel spin....check the firewall....should be like 5-6 psi.....

If they have been overinflated for awhile.....then they will have a larger circumference.....

 

[chancer]

This is useful: http://www.diygokarts.com/speed-calculator.html

 

[Poboy kartman]

Looking again....its obvious the drive tire is overinflated on that Manco Red Fox 2......

 

[Rickracer]

That's the big disadvantage with single wheel drive, take even a little weight off the left rear tire, and you're stuck/spinning. You might be able to "crutch" the situation by lowering the tire pressure on the left front and right rear, perhaps the right front a bit as well, but the best answer is making the switch to a live axle.

 

[thisismyusername]

That's the big disadvantage with single wheel drive, take even a little weight off the left rear tire, and you're stuck/spinning. You might be able to "crutch" the situation by lowering the tire pressure on the left front and right rear, perhaps the right front a bit as well, but the best answer is making the switch to a live axle.

That would make since because it is a double seater, but still it has the engine right over top of it.

 

[firemanjim]

That would make since because it is a double seater, but still it has the engine right over top of it.

But doing what he said shifts more weight to the drive wheel.
OP, get an accurate count on that axle sprocket. If it's 88, then someone changed it. I believe stack was 72.... But I've been wrong before....
I'd adjust the gear ratio for less torque, gaining more top speed. Your child's age and driving ability is limit here, as far as speed goes.
Other than that, the next best option ,in my opinion, is to go live axle. Especially since its a 2 seater. Less likely to get stuck.....

 

[chancer]

I bet it would be easy to sell that 88 tooth sprocket here too. Sounds kinda rare.

 

[thisismyusername]

But doing what he said shifts more weight to the drive wheel.
OP, get an accurate count on that axle sprocket. If it's 88, then someone changed it. I believe stack was 72.... But I've been wrong before....
I'd adjust the gear ratio for less torque, gaining more top speed. Your child's age and driving ability is limit here, as far as speed goes.
Other than that, the next best option ,in my opinion, is to go live axle. Especially since its a 2 seater. Less likely to get stuck.....

Yea live axle and change the gear ratio for less torque. But if you don't want your kids going as fast as the go kart can then you can put a screw in to limit the throttle, if the engine doesn't already have one.

 

[chancer]

Yea live axle and change the gear ratio for less torque. But if you don't want your kids going as fast as the go kart can then you can put a screw in to limit the throttle, if the engine doesn't already have one.

Not the best idea. Limiting the throttle limits the engine revs not allowing the clutch to engage fully causing premature failure.

 

[ryanpeel]

Thanks for all your help everybody. I've learned a lot from you. I will probably start another thread on converting this go-kart to a live axle.