Im building a new go kart and will use it to pull small loads. I have a 9hp engine with 2:1 reduction box. I plan on using 22" tires and a 12t sprocket on shaft and 60 tooth on axle. At 5:1 ratio would this be efficient or should I go to 7:1 or 8:1? Not looking for speed at all
Building for torque t
- Thread starter willp
- Start date
Denny
Canned Monster
With the 2:1 plus 5:1 I can’t do the math because I’m too old and slow but it should work. What CVT are you going to use? Or does it have a wet clutch. If a wet clutch you may have a problem.
It has a wet clutch in the reduction box, what problem with this cause?
Denny
Canned Monster
Slippage, centrifugal clutches don’t like big tires, heavy weights, hills, or pulling trailers. You’ll be better off selling that engine and getting one without the wet clutch.
Denny
Canned Monster
No! The shaft is far too short and an odd size also.
JimD
Well-known member
Denny has some good points but since you are not looking for any speed but what kind of terrain are you going to be riding on--flat or hilly and how much load are you talking about? Live axle or stub axle? Are we talking #35 CHAIN 0R #420 chain? with you 12/60 you would be going 23mph with your 2:1 reduction which is way to fast and hard with the huge tires you have. Switch to an 80 tooth rear sprocket will only bring it down to 17mph still to fast. The speed is coming from the large tires. Get down to a realistic tire size for a go kart like 13" then you get down to 10 mph and the clutch would love you for it. Stay with that tire size and you will be replacing a fine wet clutch in no time at all.
Denny
Canned Monster
Yea, 3/4” or 1” are common engine pto sizes for clutches and CVTs. You would need to find an engine with that size shaft.
JimD
Well-known member
Denny, you know 22mm is just a number that means nothing to a machine. I just need to know the length of the crankshaft, if it is drilled and tapped and if so what is the metric thread size. A clutch like that has to be a 2 piece clutch--separate shoe assembly from the drum and sprocket. But if it is going on monster tires again, forget it because even a Max-Torque clutch doesn't work miracles. While you are measuring you might as well give me the keyway width since that will also be metric. You can give them to me in thousands,
sample 22mm =.8661
sample 22mm =.8661
JimD
Well-known member
After talking to the gentleman and giving him several options we have re-thought the project and he is sending back the engine. It is a Ken-Bar kart and what he is going to use it for makes better sense to get a 212 engine and a series 30 T/C. I would also go down to a smaller tire not to exceed 16" in diameter and the set up will be fine. I did look up in my brochure book of the various manufacturers and the kart with those tires were single seat karts and all had torque converters. They had some with 5hp engines on them up to 11hp. I am surprised the kart would handle the 22" tires but if it was only used going down hill on pavement, maybe. He is only using it on his mile long driveway taking the garbage cans to the street. He will not be entering in the Indy 500.
ezcome-ezgo
G'me sumthin to write on
Well if he isn't entering it in the Indy 500, what's the point? Seriously.