need help making cart go!!!!!

[jrochester]

Hey guys im new here so some help would be nice. i have a early 90's carter kart, 2 seater. i have converted to clutch drive and have had issues. when the project started i replaced all axle and js bearings. my sprockets are:
Cranks shaft = 10
inner js = 10
outer js = 14
drive sprkt = 60

the issue is it will not move its like the clutch wont grab hard enough. i can roll the cart fairly decent by and and there is no binding. the clutch is new. however, it will not move. any ideas or things to check would be much appriciated.

 

[Doc Sprocket]

Its your gear ratio. You're currently at 4.28:1. Having 10 teeth on both the clutch and jackshaft in, your primary "reduction" is 1:1. A 4.28:1 final is not deep enough for a 2 seat fun kart. For a no-cost experiment, switch the two jackshaft sprockets so you have:

Clutch- 10t
J/s in- 14t
J/s out- 10t
Axle- 60t

This will result in an 8.4:1 final drive. If everything else is okay, this should move you quite well.

 

[qtband]

Let us know if that works...

 

[r_chez_08]

How big are your tyres, i.e. Tyre diameter in inches

 

[jrochester]

hey guys thanks for the help im going to try this right away. and as far as tire size goes they are, 13x5.00-6 in rear and, 4.10x3.50-5 in front. also, im not sure if this has any relevance but, i chose to go with a 40-41 chain and sprocet set-up. i'm sure its not needed however, this project is to see if i can do it. i have a single seater frame that i want to make into an actuall track cart.

 

[Doc Sprocket]

Got pics?

 

[jrochester]

i'll have to take some tommorrow and post them then.

 

[jrochester]

so this is it so far! yes it needs alot of work however, it is in the mock-up phase. if everything works corectly and how it should then it will get tore down and repainted. also, im in the process of getting a much new engine. any comments feel free to say them your not going to hurt my feelings after all it is just for fun.

 

[jrochester]

And yes the engine is nasty but runs strong. and yes once more that lazyboy tiller from the 1600's you see is where that engine came from.

 

[jrochester]

hey guys so changing to sprockets around worked awesome. however i live in the mountains and it goes but still struggles up hill on paved roads with the configuration of

crank sprkt =10
js in =14
s out =10
wheel sprkt =60

which should i change to gear it more towards the torque side? give it more hill pulling power? which sprocket and what teeth count.

 

[Doc Sprocket]

You can gear down further for more pulling power, at the sacrifice of speed. Ultimately, if you do a lot of hills, you're better off changing to a CVT.

Meanwhile- That 14T j/s in sprocket could be replaced with a larger one. You're at 8.4:1 now. According to my math, theoretical top speed at 3600RPM is 16.57MPH. If that 14T were a 16T, your overall reduction ratio would be 9.6:1, with a theoretical top speed of 14.5 MPH and an approximately 12.5% increase in torque. How slow are you willing to go?

 

[jrochester]

honestly at this point its almost to slow. however if it doesnt go up and down the yard its not doing much good for the kids either. so im still learning this what is a cvt? and second this is kinda on another subject but its another kart im ddebating on, i have a suzuki ds 80 which is a two stroke dirt bike with five speed gear box would this engine be enough to have a pretty fun and peppy kart?

 

[Doc Sprocket]

A CVT is a Continuously Variable Transmission. Aside from karts, they are widely used on snowmobiles and even golf karts. For out purposes, research Comet 40, and TAV, or Torq-A-Verter. System is characterised by two self-adjusting pulley sheaves connected by a belt. It is like having an automatic transmission that allows variable, smooth gearing. The major benefit is that it will allow a low take-off ratio for plenty of torque, while still allowing a respectable top end.

An 80cc 2-stroke might be a bit weak for the purpose, but I'm quite sure it would do better than what you have, with appropriate gearing.