5.5hp 10t Clutch & 60t sprocket 17" Tires....good combo?

[ur2noz]

Judging by the above info can tell me is this a good combo for my newly aquired cart. Looks to be a 6:1 ratio which I understand from reading is a nice start. Little concerned about the tire size being to large. They are 18x8.5x8 all the way around.


Thanks
Adam

 

[tykenfitz]

http://www.diygokarts.com/speed-calculator.html

Assuming your motor is governed to 3600rpm, you should go about 32mph, so it's probably an OK ratio, how much do you and the cart weigh?

 

[redsox985]

Is it a cent. clutch or a torque converter?

 

[ur2noz]

I would imagine the kart and myself would be about 360lbs the kart being 200 of that.

The clutch is centrifical.

 

[Russ2251]

Assuming #35 chain, kart will perform far better using a driven sprocket at least double the size of what you are currently using. 60 teeth is far too small for 17" diameter tires. Clutch will burn and acceleration will be less than desirable.

 

[ramairgtz]

I have the same 6:1 ratio with 18" tires on one of my other karts and it doesn't take off very well at all. Once it's moving it is pretty quick so I'm going to use a jack shaft to change the ratio higher and it should be good then. Best thing for you would be a torque converter. I'm selling this kart so I don't want to spend the money on one for mine

 

[ur2noz]

Assuming #35 chain, kart will perform far better using a driven sprocket at least double the size of what you are currently using. 60 teeth is far too small for 17" diameter tires. Clutch will burn and acceleration will be less than desirable.

You sir are correct. Brand new clutch installed. #41 chain setup yet the cart takes off like I am pulling a boat behind it and the clutch smokes like a train? What would be my cheapest solution to this problem? If i went to a 16x6.5x8 tire would it help that much?

 

[ur2noz]

I was doing some reading, looks like the overall tire size is certainly to large. The main sprocket should be approximately the same diameter as the tires? My main sprocket is 11" yet I can only run so so small of a tire before the sprocket and disc brakes are trenching the grass because it is so low. It looks like this Kart originaly had a torque convertor installed as there is brackets behind the non-original engine.

 

[Russ2251]

As a general rule, axle sprocket diameter should be within about 1.5 to 2 inches of tire diameter as a starting point.

 

[ramairgtz]

You sir are correct. Brand new clutch installed. #41 chain setup yet the cart takes off like I am pulling a boat behind it and the clutch smokes like a train? What would be my cheapest solution to this problem? If i went to a 16x6.5x8 tire would it help that much?

Cheapest solution if you wanted to keep the same tires would probably be a jack shaft. Run the chain from the 10t on the clutch to a lets say 14 tooth on the shaft. On the other side of the shaft run a chain from a 10t to the 60t on the axle and that should change the gear ratio enough to give it some bottom end but you may loose top speed.

 

[Russ2251]

Top speed is meaningless if it takes forever to get there or if there is not enough room (distance).

 

[ur2noz]

Cheapest solution if you wanted to keep the same tires would probably be a jack shaft. Run the chain from the 10t on the clutch to a lets say 14 tooth on the shaft. On the other side of the shaft run a chain from a 10t to the 60t on the axle and that should change the gear ratio enough to give it some bottom end but you may loose top speed.

I can go smaller on the tires but 16x8.5x8 is about as small as I can go before the main drive gear starts to get real close to the ground, as I go over high spots in my lawn I know its going to start digging a trench LOL

Where can I get a jackshaft from?

 

[ramairgtz]

I have 13x6.5-6 tires on my small kart with a 60t rear sprocket and never had any problems.

You can find jack shafts on ebay, bmi karts, mfg supply I may do mine tonight so I'll take some pics

 

[redsox985]

Just a side note. Do not use 41 chain, use 40. It's considerably stronger.

 

[ur2noz]

Thanks and pics are appreciated. I have included a pic of my setup. I do not know the original factory configuration of the drive line on this cart. If you look at the black bracket to the right of the engine it appears this might have had a jackshaft? That bracket contains a bearing but how it plays a part I have no clue

 

[redsox985]

That looks like a torque converter backplate. Or the remnants of one. And a dog. I believe that's a dog's a$$. Lol.

 

[Blazkowiez]

You're correct on that Red, his Ken-Bar came with a torque converter when it was new.

Switching to a 16" tall tire will make a huge difference though for your application a torque converter would be the best investment. I wouldn't attempt to do straight chain drive with any tire taller than 16"...

Baja Motorsports put out a kart a few years ago which had the same problem from factory that you're running into, kids would smoke clutch after clutch... we had to fix kart after kart when customers brought them to us trying to figure out what was wrong.

 

[ur2noz]

You're correct on that Red, his Ken-Bar came with a torque converter when it was new.

Switching to a 16" tall tire will make a huge difference though for your application a torque converter would be the best investment. I wouldn't attempt to do straight chain drive with any tire taller than 16"...

Baja Motorsports put out a kart a few years ago which had the same problem from factory that you're running into, kids would smoke clutch after clutch... we had to fix kart after kart when customers brought them to us trying to figure out what was wrong.

I truelly have no clue how to install a torque convertor. Can you give me some more direction as to where the convertor would go and or shoot me a web site to get one from? I don't mind putting $100 in new smaller tires on the kart if it truelly would make a difference. However I still don't want to be going through $40 clutches all the time.

 

[ur2noz]

You're correct on that Red, his Ken-Bar came with a torque converter when it was new.

Switching to a 16" tall tire will make a huge difference though for your application a torque converter would be the best investment. I wouldn't attempt to do straight chain drive with any tire taller than 16"...

Baja Motorsports put out a kart a few years ago which had the same problem from factory that you're running into, kids would smoke clutch after clutch... we had to fix kart after kart when customers brought them to us trying to figure out what was wrong.

I honestly have no clue how to install a torque convertor. Can you give me some more direction as to where the convertor would go and or shoot me a web site to get one from? I don't mind putting $100 in new smaller tires on the kart if it truelly would make a difference. However I still don't want to be going through $40 clutches all the time.

 

[redsox985]

Well a TC bolts right onto the face of the motor, assuming you got the 30 series or the GTC copy. It's relatively simple. You'd just need to adjust the chain.