go kart centrifical clutch problems.

Messages
5
Location
Michigan
Hello everyone I am new to this site ant the whole go kart thing as well. I could really use some advice because I'm sinking. My go kart has a 6.5 honda. It runs fantastic and my go kart would be top notch if I could run it for more than 2 minutes! The centrifical clutches keep overheating and breaking. I have 150.00 in clutches alone. My bore is 3/4 and my axel is 1in. 35 chain 10 tooth clutch aND 36 teeth on sprocket. know one seems to know what's wrong. The chain has about 1/2in play in it as I am told is neccarry. WHat can I do to make this thing run all day? 2 mins of fun is just not worth it!!!! Please help me!
 
Messages
15,859
Location
NE,Ohio
http://gokartsusa.com/clutchinfomaintenance.aspx any of that help? of particular interest is the fact that you may not be running the correct gear ratio. they suggest aprox 6:1 what size tires? I found that in about 15s goto google.com type in go kart clutches overheating might see other issues, I'm not an expert or even amateur in go-karts.
 
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Jasonpaul

Thread starter
Messages
5
Location
Michigan
My tires are 15 in tall and about 6in wide. I'm told it's a 6:1 but I'm told it's not likely that's the problem.i will get a 60 tooth tomorrow if you think that will help. Some are saying a torque converter would do it bit I know nothing about that. should I be doing anything to the clutch other than installing it? I just slap it on and try it out but it always fails
 

Jasonpaul

Thread starter
Messages
5
Location
Michigan
Now that I see your chart I feel like I need a bigger rear sprocket! That gave me a glider of hope:) can't wait to see what tomorrow brings! Being that my rear tires are a bit on the big size should I go a bit bigger than 60 or smaller?
 
Messages
2,923
Location
Georgia/Retired
I think the whole issue is with the 10 tooth drive/36 tooth driven ratios (not anywhere near a 6:1 ratio). Get a big frisbee disk on the back (ie: 60 tooth) and watch that baby fly.
 
Messages
4,478
Location
Central Arkansastan
It is overheating because of slippage. Probably because of the tooth count not high enough. It doesn't take much to slip these clutches, and if your gears are too high or cart is overloaded (rider + cart weight) they will slip
 
Messages
15,859
Location
NE,Ohio
15" are abit on the big size, you might need to run a torque converter I'd start at 60 if that's better but still slipping maybe one more size up (66?72?) If you read that link I posted they have some good advice in there. 36 is way off.. so first step is trying a 60.
 

Jasonpaul

Thread starter
Messages
5
Location
Michigan
60 was better by far but it still got hit after about 5 minutes amd I had to shut it down and 1 hour later it was still warm. I have the greyhound 6.5 it's a honda clone can I put a torque converter on that engine? I have searched for hours! My bore is 3/4 but my rear axel is 1inch if that makes a difference. If I can put one on what one?????? And would I still have the centrifical clutch on? I just ordered a 72 tooth rear sprocket will I still need that? I'm so lost please help!
 
Messages
15,859
Location
NE,Ohio
you need to do some research. also what quality of parts are you using. there is everything from 39$ to 180$ clutches same for torque converters.(and the TC replaces the clutch) some simple google searches would help you more than posting here. if you get a cheap TC you could possibly have problems too. Sounds like you are in abit over your head.
 
Messages
15,859
Location
NE,Ohio
might start by reading this http://www.bmikarts.com/10-Things-to-Know-about-a-Centrifugal-Clutch_ep_63-1.html TC is more foolproof.. but you shouldn't have that many issues with your clutch. Obviously being way off on the ratio was killing it before.. but you could have other issues that are just now becoming apparent. Plenty of reading out there available to be found with 15s of your time and google.com ripping off a few of their points from that link
Quote:
Changing the size of the tires. Putting on tires that are larger than what came with the kart will result in clutch problems. Tires exceeding 13" in diameter stress out a clutch if the kart is not properly geared for the larger tires. If you are driving on smooth flat terrain than you may be able to get by with 14" tires but once you get on hilly terrain, deep grass, then you are putting additional strain on the clutch, which will cause premature wear. Big tires look neat on a go-kart but you create your own problem changing to a bigger tire when the clutch isn't designed to handle them. Weight. A centrifugal clutch is designed to be able to move a certain amount of weight. Once the weight limit is exceeded, then the life of the clutch will be shortened. A good rule of thumb is the kart and driver (and passenger when it is a two seat kart) should not exceed 400 pounds. The kart weighs around 150 pounds add to this the driver (and passenger weight, if it is a two seater kart). If you know ahead of time that you will exceed the 400 pounds then buy a torque converter go-kart and avoid the problems of burning up the clutch asking it to do more than it was designed for. Gear ratio. The sprocket on the engine and the one on the rear axle should have a ratio close to 1:6. This means for every tooth on the clutch there are six teeth on the rear sprocket. So if you count 10 teeth on the clutch there should be 60 teeth on the rear sprocket. (12 teeth on the clutch means a 72 teeth rear sprocket). A torque converter has a variable speed system between the driver and the driven pulleys so it can improve upon this ratio, which gives the torque converter an advantage over a straight clutch system. It improves the ratio by approximately 3:1 and can turn larger tires and drive at slower speeds without doing any damage to the clutch system. A torque converter is a more expensive system initially but it will last longer and is more trouble free when maintained.
 
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Messages
4,894
Location
Southeast
agree with all of the above. driving under 6:1 is like trying to drive a car around town in 6th gear--- it's not right. The centrifugal clutch doesn't grab well at lower rpms, and it's forced to stay there with the incorrect ratio. Plus, larger tires acts like even less ratio. you'll need a good bit more than 60 tooth with the big wheels. This will all reduce your top speed, but you can't likely achieve top speed now anyway with the mis-matched gearing. Be patient--- you may try to read up on gear ratios and wheel sizing. Finding someone who understands geometry can also help you with the math to work it out.
 
Messages
15,859
Location
NE,Ohio
Originally Posted By: meep
agree with all of the above. driving under 6:1 is like trying to drive a car around town in 6th gear--- it's not right. The centrifugal clutch doesn't grab well at lower rpms, and it's forced to stay there with the incorrect ratio. Plus, larger tires acts like even less ratio. you'll need a good bit more than 60 tooth with the big wheels. This will all reduce your top speed, but you can't likely achieve top speed now anyway with the mis-matched gearing. Be patient--- you may try to read up on gear ratios and wheel sizing. Finding someone who understands geometry can also help you with the math to work it out.
I wouldnt order anything without research but I think a high quality TC would definitely solve many of your problems.. that being said a 6:1 ratio is right for normal tires, if your tires are too big or the gokart with rider too heavy (400lb) a clutch is still going to struggle.
 
Messages
19,686
Location
Sunny Florida
with such poor gearing even a TC may have issues. A centrifugal will over heat and die quickly if it can't 'lock up' and go into direct drive eventually...
 
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