Clutch overheating

[Basn12]

I have a go kart with. 3.4:1 ratio (10T clutch/ 34T axel sprocket) but my clutch keeps over heating, any tips on how to fix it WITHOUT changing axel sprocket (pic is before i put clutch in)

 

[BrownStainRacing]

I have a go kart with. 3.4:1 ratio (10T clutch/ 34T axel sprocket) but my clutch keeps over heating, any tips on how to fix it WITHOUT changing axel sprocket (pic is before i put clutch in)View attachment 141698

It'll never work with a clutch.

That buggy is too heavy and tires are too big for a clutch to work.

A big block 420cc can't even pull that, and it makes 20 ft/lbs of torq.

Your small block hemi makes around 9.5 ft/lbs torq.

9.5 x 3.4 = 32.3 ft/lbs to the axle.
That might be enough for a small tire mini bike with a 50 lb rider.

You're gonna need a 30 series t/c with a 7" driven and at least a 50t axle sprocket.

A 20 series would be the better option, but still gotta change that axle sprocket.

 

[Basn12]

How much do you think it’ll go for as is?

 

[panchothedog]

Your question as written makes no since. Are you talking dollars or miles per hour? You can buy a new complete 30 series torque converter on Amazon for around $70. Your axle sprocket is still way too small. It should be a 60 tooth sprocket being driven by the 10 tooth sprocket that will come with the torque converter. If you are too lazy, cheap, or incompetent ( your choice ) to change the axle sprocket, you could replace the 10tooth with a 9 tooth or better yet a
8 tooth. With the 8 tooth the kart will give you satisfactory take off acceleration, but still be way too high geard for any hill climbing. With a 10 x 60 combo it will go almost anywhere and climb very steep hills. With the stock governor connected your kart will probably go somewhere in the 30-35 mph range.

 

[panchothedog]

Maybe you were asking how how much you could sell it for as it sits. If that was your question, then the answer is just as much as you can get somebody to pay you for it. A running, driving, kart is a much easier sell than a project, and would probably bring double the money.

 

[JimD]

Most people like to buy a running machine. You already know a clutch will not work. Even if you changed to a t/c you have to increase the rear sprocket to at least 60 teeth. It is a nice kart but if you want to get a good "buck" for it you will have to put some money into it and once you do that most likely you will want to keep it.

 

[Basn12]

Your question as written makes no since. Are you talking dollars or miles per hour? You can buy a new complete 30 series torque converter on Amazon for around $70. Your axle sprocket is still way too small. It should be a 60 tooth sprocket being driven by the 10 tooth sprocket that will come with the torque converter. If you are too lazy, cheap, or incompetent ( your choice ) to change the axle sprocket, you could replace the 10tooth with a 9 tooth or better yet a
8 tooth. With the 8 tooth the kart will give you satisfactory take off acceleration, but still be way too high geard for any hill climbing. With a 10 x 60 combo it will go almost anywhere and climb very steep hills. With the stock governor connected your kart will probably go somewhere in the 30-35 mph range.

Yea but for me to go 60T i would need to cut up the frame, i was wondering if there was an alternative. So i can make a easy sale

 

[Basn12]

Your question as written makes no since. Are you talking dollars or miles per hour? You can buy a new complete 30 series torque converter on Amazon for around $70. Your axle sprocket is still way too small. It should be a 60 tooth sprocket being driven by the 10 tooth sprocket that will come with the torque converter. If you are too lazy, cheap, or incompetent ( your choice ) to change the axle sprocket, you could replace the 10tooth with a 9 tooth or better yet a
8 tooth. With the 8 tooth the kart will give you satisfactory take off acceleration, but still be way too high geard for any hill climbing. With a 10 x 60 combo it will go almost anywhere and climb very steep hills. With the stock governor connected your kart will probably go somewhere in the 30-35 mph range.

Will i blow my t/c if i dont change my axel sprocket?

 

[BrownStainRacing]

Will i blow my t/c if i dont change my axel sprocket?

You will burn up belts about every 15 minutes of riding.

Theres jus not enough torque to move that weight and tire size.

Gear ratio is a torq multiplier.

You are gonna need at least 150 ft/lbs to the axle, to get it moving.

Yes a 60t would be better, but I can see it will not fit your frame, without cutting.

That's why I mentioned the 7" driven and at least a 50t.

50/10= 5:1
50/9= 5.55:1
50/8= 6.25:1

A 7" driven with a 30 series driver has a 3.13:1 low gear ratio

3.13 × 6.25 x 9.5 = 185 ft/lb of torq to the axle.

That'll get it moving.

 

[JimD]

I looked again at the kart and those cross pieces you put in for the engine will NOT be stiff enough. They will flex too much when those tires bit in. Plus you don't have any forward movement for the engine to compensate for chain stretch. You would have been better off with a piece of angle iron to give you some structural strength. All these things can be fixed but you have a project on your hands. I will admit I didn't see how close the rear axle was to the frame and that certainly is a problem. Moving the axle forward will effect the handling of the kart. Cutting the chassis and moving the bumper back would be my choice but now finding the right match up in tubing if it is a china kart will give you fits because metric and English measurements are not even close so having a friend with a lathe will now be your next task. About now you say why did I buy this in the first place?? It is a fun project and when you are all done you have that sense of accomplishment and you will conclude you were a better engineer then the original jackbutt that made this kart in the first place and you will be right!!!

 

[BaconBitRacing]

Unfortunately all of these guys are right. This kart, to be a good, usable kart, needs a TC and fabrication to fit a 60T sprocket. Or at least a 54T with a 9T driver.

 

[panchothedog]

In my 1st post I was looking at your kart only from a clutch, acceleration problem standpoint. After reading JimD's most recent posts, looking at how your engine is mounted, you have a bigger problem yet. If you ever did get the kart going, three two flat pieces that the engine sitting on will start flexing so bad that your drive chain won't know if it's coming or going. They need to be 3/16 angle, or 1/8 wall square tubing min. And then weld a standard motor mount plate across them, so you have some for and aft movement for chain adjustability. If you were to have a shop fabricate a couple of pedestals to raise up your new stronger cross members a couple of inches you would now have plenty of room for a bigger axle
sprocket. Talk to folks at a couple of welding shops, or muffler shops. Not everyone wants to work on a go kart. But some will. I'm guessing you could get the back end of your kart straightened out for $100, plus the price of a motor plate. After that the torque converter and a 60 tooth sprocket. You still need to invest about $250 and several hours of elbow grease to finish it up. If you do, you will have a very nice fully suspended go anywhere kart. If not, cut your losses and
sell it as is for whatever you can get for it.

 

[bob58o]

Smaller tires.
If your tire was half as tall, it’s the same as using a 68T sprocket instead of a 34T.

 

[panchothedog]

Smaller tires! Best idea anyone has come up with.

 

[bob58o]

My other idea was to Flintstone it.
Or only drive down hill. Lol

 

[bob58o]

If you had 10” tires, the clutch will slip and burn until you reach 18 mph.

If you have 18” tires, the clutch will slip and burn until you reach 32mph.

(if clutch engagement is 2000 rpm).

Maybe if you can idle at 900RPM ? And find a clutch that engages at 1000 rpm, but I’m not sure if these engines idle that low. Also not sure if the engine produces any torques at 1000 rpm ?

You might could try a TC with 8T sprocket and 7” driven unit.
4.25 :1 sprocket ratio.
3.10 :1 pulley ratio at clutch engagement.
13.2 :1 over all reduction at 2000 rpm

8 or 9 mph at clutch engagement even with 18” tires.

It’d be geared for like 45mph at 3600 Rpm’s so you might still be burning up belts.

 

[Hellion]

I looked again at the kart and those cross pieces you put in for the engine will NOT be stiff enough. They will flex too much..... Plus you don't have any forward movement for the engine to compensate for chain stretch.

Yeah, saw that too. I bet that engine has some nice wobble at idle and at all speeds.

You need a thick sturdy plate, 3/16" to 1/4" inch thick, with slotted holes (in the forward and back direction) to allow the engine to slide forward to account for chain stretch. Best to mount the engine all the way back on the mount slots, fit your chain, and then you'll have lots of room to slide it forward when you need to. Always sounds so primitive when I explain that but chain stretch and slack is adjusted on a motorcycle by moving the rear wheel in and out, so there.

Price is whatever someone is willing to pay. Premium prices are for a fully functional kart however. For yours maybe $100-150 price on the frame alone and then add the cost of the engine I guess (maybe minus 30-40 bucks). It looks new (labels and everything still on it) but it still depreciates in value once it comes out of the box.

 

[pearl111]

My other idea was to Flintstone it.
Or only drive down hill. Lol

Looks like Wilma and Betty are ready to go too.

 

[Denny]

I always thought Betty was kinda hot!