Riley,couple drops of oil on the clutch bushing(only). caution do not get any oil on anything else,for example inside the clutch unit shoes. you should be able to move the clutch unit back and forth about 1/16 or less still on the crankshaft and there will be a very small gap for you to drop little oil on. unless you take the whole thing apart. i don't think you need to do that. last summer the kids road doodle bugs alot and found my self doing that alot. probable twice a month or so. they can get dry and dusty sometimes real quick.
is it bad to get oil inside the clutch? well yes and no
what would that do?
well if you do get oil in the clutch it will suck for a bit . it will slip bad and get very hot and stink, smoke . ya i have made that mistake before .it will burn the oil out and start to work again. can be real hard on the shoes , so try to avoid getting oil on them
what would that do?
well if you do get oil in the clutch it will suck for a bit . it will slip bad and get very hot and stink, smoke . ya i have made that mistake before .it will burn the oil out and start to work again. can be real hard on the shoes , so try to avoid getting oil on them
Here is an excerpt from Go Kart Parts | Go Kart Supply Online Catalog. It refers to go-karts, but the same applies to mini bikes. Check out what is in red.
Centrifugal Clutch Tips
Driving Habits That Can Ruin A Clutch
1) Driving too slowly: A centrifugal clutch starts to engage around 2,000 rpm and will lock up around 2,600 rpm. Driving at speeds that allow the clutch to fully engage gives the clutch a chance to cool down. When the clutch is allowed to fully engage it locks the shoes in the clutch against the drum. When the clutch is not locked up, the shoes slip against the drum causing tremendous heat which dries up the lubrication in the oil impregnated bronze bushing. The tremendous amount of heat generated can also anneal the spring which is the heart of the clutch. If the shoes turn a blue-purple color from excessive heat, it's more than likely the clutch is ruined and the spring no longer has the ability to pull back the shoes at idle.
2) Short stop and go driving: The longer you drive at high throttle the better off it is for the clutch because it gives the clutch a chance to cool off before the next engagement. When the clutch is fully engaged there's no wear going on.
3) Driving with the foot on the brake: This is a problem with new drivers that are unsure of themselves. When riding a go kart for the first time, try to find an open area that has no obstacles that you have to maneuver around until you get use to the brake and gas pedals. The driver must first be able to build up his or her confidence on the kart before putting obstacles in their path. A small back yard is not a good place to learn to drive a go-kart. In my opinion, a minimum of ¾ of an acre is the yard needed for a go kart. Teach your child to drive with one foot on the pedal be it the brake or the gas but not to press on both pedals at the same time. You either want to go or to stop but you cannot do them both at the same time.
4) 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 cool on a go kart but you create your own problem changing to a bigger tire when the clutch isn't designed to handle them. If you have tires over 15" tall you are required to use a torque converter instead of a centrifugal clutch. Do not install rims larger than six inches if your go kart is equipped with a centrifugal clutch.
5) 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. 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.
6) Restrictions: Do not try and reduce a kart's speed by limiting the travel of the gas pedal or by putting a restrictor in the carburetor to limit full rpm. Either of these methods will result in the clutch slipping, which is self-destructive. A clutch needs full rpm to lock up as quickly as possible to be able to start to cool down. To slow down a go-kart you would need to purchase a gear reduction unit, which is like training wheels on a go-kart until the driver gets accustomed to how the go-kart handles. A gear reduction unit can reduce the speed of the go-kart in half.
How can I prolong the life of a centrifugal clutch?
1) Oil the bushing that is located in the sprocket at least every two (2) hours of driving time. Where do you oil it? Right where you see the snap ring on the sprocket at the end of the clutch. There is a bronze bushing behind the snap ring that needs lubrication. With the engine off, squirt several drops of oil while the bushing is warm. At the same time oil the chain. What oil should I use? A good automotive oil like 10w30 or a straight 30HD weight oil is good, use the same oil used inside the engine. Once the chain gets "kinky" from lack of oil it should be replaced before it does damage to the clutch sprocket. A new chain is cheaper than a new clutch. If you keep the clutch and chain lubricated you should get years out of both. Oiling the chain after it gets dried out is a waste of time. Remember it is preventive maintenance, which means before the items get ruined.
2) Don't put oil inside the clutch. The holes on the drum of the clutch are to let the hot air out of the clutch. DON'T SQUIRT OIL IN THESE HOLES!! When oil gets in the drum portion of the clutch it will cause excessive slippage, which means undue heat will be generated.
3) The oils that can give you problems if they happen to get on your brake disc or in the drum of your clutch are: Slick 50, Dynamite, or Energy Release. These are excellent internal engine oils but will give you "fits" if they get inside the clutch or on the brake disc. They do just what they are intended to do which is to prevent friction -- steel to steel contact. On a clutch you need friction to have it engage and the same goes for a brake system. Because the oil comes out in very minute amounts and gets on the inside of the clutch drum. The clutch would only slip, it would not and could not lock up. This oil will impregnate the steel. Sanding and cleaning with a solvent or gas will not help. Once it is in the metal, it is in there forever because the heat will bring these lubricants back to the surface.
4) If your kart has a grease fitting in the crankshaft for lubrication then a shot of grease twice a month should be sufficient lubrication. The grease is coming from the inside of the sprocket outward, which is a better way to lubricate the clutch. The keyway in the crankshaft acts as a reservoir for the grease, which cuts down on the frequency needed for maintenance compared to oiling the snap ring area. The chain still needs to be oiled frequently to keep it from kinking up. There are some excellent chain sprays available that are waxy and will not let sand and dirt adhere to them. Dirt and sand will wear the chain as well as the sprockets.
If your go kart takes off by itself when the engine is started, with no one in the drivers seat, that is an indication that the clutch is badly in need of lubrication. Turn the engine off and park the machine up against a tree or fence to prevent it from taking off when you crank the engine again. You can also put the rear end up on centerblocks so the rear wheels are not touching the ground. Lubricate as needed. Give the lube enough time to penetrate, then start the engine. If the machine continues to take off by itself even after the clutch has been oiled, the clutch is burned up and must be replaced.
How long will the clutch last?
If put on the crankshaft properly and observing all the hints that are pointed out in this article, a clutch should last many years. But if it is improperly installed, driven in abusive conditions (lack of oil, sand, steep terrain, excessive weight in the kart, wheels that are to tall), the clutch might only last 20 minutes.
Teach your child how to do the maintenance on the kart or mini bike and accept responsibility for its upkeep. Every second tank of gas in the kart is about the interval for oiling the chain and the bushing. Oil the clutch even more often if an unexperienced driver is riding the machine around slow without gaining enough speed to engage the clutch all the way. If your child learns to do this preventive maintenance your machine should be enjoyable for many years. Who knows, if the kart is taken care of you may one day watch your children's children ride the machine, Priceless.....
Centrifugal Clutch Tips
Driving Habits That Can Ruin A Clutch
1) Driving too slowly: A centrifugal clutch starts to engage around 2,000 rpm and will lock up around 2,600 rpm. Driving at speeds that allow the clutch to fully engage gives the clutch a chance to cool down. When the clutch is allowed to fully engage it locks the shoes in the clutch against the drum. When the clutch is not locked up, the shoes slip against the drum causing tremendous heat which dries up the lubrication in the oil impregnated bronze bushing. The tremendous amount of heat generated can also anneal the spring which is the heart of the clutch. If the shoes turn a blue-purple color from excessive heat, it's more than likely the clutch is ruined and the spring no longer has the ability to pull back the shoes at idle.
2) Short stop and go driving: The longer you drive at high throttle the better off it is for the clutch because it gives the clutch a chance to cool off before the next engagement. When the clutch is fully engaged there's no wear going on.
3) Driving with the foot on the brake: This is a problem with new drivers that are unsure of themselves. When riding a go kart for the first time, try to find an open area that has no obstacles that you have to maneuver around until you get use to the brake and gas pedals. The driver must first be able to build up his or her confidence on the kart before putting obstacles in their path. A small back yard is not a good place to learn to drive a go-kart. In my opinion, a minimum of ¾ of an acre is the yard needed for a go kart. Teach your child to drive with one foot on the pedal be it the brake or the gas but not to press on both pedals at the same time. You either want to go or to stop but you cannot do them both at the same time.
4) 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 cool on a go kart but you create your own problem changing to a bigger tire when the clutch isn't designed to handle them. If you have tires over 15" tall you are required to use a torque converter instead of a centrifugal clutch. Do not install rims larger than six inches if your go kart is equipped with a centrifugal clutch.
5) 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. 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.
6) Restrictions: Do not try and reduce a kart's speed by limiting the travel of the gas pedal or by putting a restrictor in the carburetor to limit full rpm. Either of these methods will result in the clutch slipping, which is self-destructive. A clutch needs full rpm to lock up as quickly as possible to be able to start to cool down. To slow down a go-kart you would need to purchase a gear reduction unit, which is like training wheels on a go-kart until the driver gets accustomed to how the go-kart handles. A gear reduction unit can reduce the speed of the go-kart in half.
How can I prolong the life of a centrifugal clutch?
1) Oil the bushing that is located in the sprocket at least every two (2) hours of driving time. Where do you oil it? Right where you see the snap ring on the sprocket at the end of the clutch. There is a bronze bushing behind the snap ring that needs lubrication. With the engine off, squirt several drops of oil while the bushing is warm. At the same time oil the chain. What oil should I use? A good automotive oil like 10w30 or a straight 30HD weight oil is good, use the same oil used inside the engine. Once the chain gets "kinky" from lack of oil it should be replaced before it does damage to the clutch sprocket. A new chain is cheaper than a new clutch. If you keep the clutch and chain lubricated you should get years out of both. Oiling the chain after it gets dried out is a waste of time. Remember it is preventive maintenance, which means before the items get ruined.
2) Don't put oil inside the clutch. The holes on the drum of the clutch are to let the hot air out of the clutch. DON'T SQUIRT OIL IN THESE HOLES!! When oil gets in the drum portion of the clutch it will cause excessive slippage, which means undue heat will be generated.
3) The oils that can give you problems if they happen to get on your brake disc or in the drum of your clutch are: Slick 50, Dynamite, or Energy Release. These are excellent internal engine oils but will give you "fits" if they get inside the clutch or on the brake disc. They do just what they are intended to do which is to prevent friction -- steel to steel contact. On a clutch you need friction to have it engage and the same goes for a brake system. Because the oil comes out in very minute amounts and gets on the inside of the clutch drum. The clutch would only slip, it would not and could not lock up. This oil will impregnate the steel. Sanding and cleaning with a solvent or gas will not help. Once it is in the metal, it is in there forever because the heat will bring these lubricants back to the surface.
4) If your kart has a grease fitting in the crankshaft for lubrication then a shot of grease twice a month should be sufficient lubrication. The grease is coming from the inside of the sprocket outward, which is a better way to lubricate the clutch. The keyway in the crankshaft acts as a reservoir for the grease, which cuts down on the frequency needed for maintenance compared to oiling the snap ring area. The chain still needs to be oiled frequently to keep it from kinking up. There are some excellent chain sprays available that are waxy and will not let sand and dirt adhere to them. Dirt and sand will wear the chain as well as the sprockets.
If your go kart takes off by itself when the engine is started, with no one in the drivers seat, that is an indication that the clutch is badly in need of lubrication. Turn the engine off and park the machine up against a tree or fence to prevent it from taking off when you crank the engine again. You can also put the rear end up on centerblocks so the rear wheels are not touching the ground. Lubricate as needed. Give the lube enough time to penetrate, then start the engine. If the machine continues to take off by itself even after the clutch has been oiled, the clutch is burned up and must be replaced.
How long will the clutch last?
If put on the crankshaft properly and observing all the hints that are pointed out in this article, a clutch should last many years. But if it is improperly installed, driven in abusive conditions (lack of oil, sand, steep terrain, excessive weight in the kart, wheels that are to tall), the clutch might only last 20 minutes.
Teach your child how to do the maintenance on the kart or mini bike and accept responsibility for its upkeep. Every second tank of gas in the kart is about the interval for oiling the chain and the bushing. Oil the clutch even more often if an unexperienced driver is riding the machine around slow without gaining enough speed to engage the clutch all the way. If your child learns to do this preventive maintenance your machine should be enjoyable for many years. Who knows, if the kart is taken care of you may one day watch your children's children ride the machine, Priceless.....
