Clutch always engaging

#1
Hey guys,

Thanks for all of the great info on this site. I was on the fence about getting a DB30 and after seeing some of the cool stuff on here had to get it. I bought it slightly used and knew exaclty what to expect from info found here, little power for my 225lb unless hauling :censure: downhill!. I picked it up Sat and rode all day Sunday with my son.

My question is about the clutch. When I have the bike idle the rear wheel spins(picking up the rear end). Is there an adjustment that I can make? The throttle cable seems to stick also and I have to turn it back to let off the throttle. Any help will be greatly appreciated.

Another question is about the engine and rear sprocket swaps. I am already planning a motor, but was thinking of changing the rear sprocket first to get more low end. Can these upgrades be done together or should you do one or the other (engine or sprocket)?

Thank you. Making it my own now and pics to come.
 
#2
dont change the sprocket a 60 tooth is fine but the engine u should change also there is a big black screw above the carburator which maintians gas flow into the engine at idle speed so unscrew that a couple screws and hopefully it will stop spinning but beware if u unscrew it too much then it will cause the bike to shut off every couple minutes when idling cause it doesnt get enough gas but if your getting a new engine soon dont be too worried
 
#3
I appreciate the info about the sprocket, sounds like both ways have some advantages, but a bigger motor and clutch are better for my needs. Are you talking about the air/fuel mixture screw? I have adjusted it to run pretty good. The motor runs great, but the clutch doesn't seem to engage properly. I haven't taken anything apart yet. Is there something to lube in the clutch?
 
#4
well sort of if you had ur bike for a while and not cleaned it then yes in your clutch you can take the clutch guard off then you take an air compressor and blow the dust and shi* out of there especially the big hole in it. Also after that you can put a little oil on the small sprocket in the clutch thats the only place u can lube it TRY IT GOOD LUCK
 
#5
does it make any noise? when i've broken springs in mine it stays engaged. one time it made some nasty noises and the other two i didn't realize it until looking at the clutch.
 
#6
It doesn't make any abnormal noises, I took off the cover and everything looks good. I am going to ride it more and break it in to see what happens. I may just take apart the clutch a take a look. I bought it to mess with so this is a good place to start.
 
#7
....Also after that you can put a little oil on the small sprocket in the clutch thats the only place u can lube it TRY IT GOOD LUCK
Huh? :eek: Where'd you come up with that? :eek:ut:

Almost every 'dry style' centrifugal clutch requires specific & regular lubrication. I believe every 2 to 4 hours of operation is the usual recommended interval.

The following "Maintenance Tech Tips" were copied from: Extreme Duty Centrifugal Clutches

The centrifugal clutch whether it is being used in a minibike or a go-kart needs to be lubricated each day that you ride. To get best results oil the clutch before and after each time that you ride. YOU CAN NEVER OIL THE CLUTCH TOO MUCH. It is a good idea to oil the chain at the same time that you oil the clutch.

The Hilliard Extreme Duty clutch contains an oil impregnated bronze bushing. 20% of the weight of the bushing is the oil that is impregnated into the bushing by the manufacturer. This oil can leak out, or can evaporate over time, and must be replaced. The bushing is a loose fit into the sprocket and is driven by the crankshaft. A snapring holds the bushing into the sprocket on all LD4S-“x”L series clutches. The LD4S-“x” series clutches DO NOT HAVE A SNAPRING.

To oil the clutch bushing shut the engine off, apply standard organic motor oil (SAE 10w-30) to the snap ring area. DO NOT USE SYNTHETIC MOTOR OIL’S because the special additives in these oils prevent the required steel to steel contact between the clutch shoes and the clutch drum. Loosing this steel to steel contact will make the clutch slip, reducing its torque transmission to the ground. Be sure to oil the bushing on all sides. To ensure that the oil is evenly spread out over the bushing surface rotate the clutch housing (the part attached to the sprocket). Oiling the clutch while it is warm will allow the porous bushing to soak up more oil, and will help replenish the oil that was inside the bushing when it was new.

Thoroughly cleaning the dirt from the clutch will help prolong its life. Dirt is abrasive and can act like sandpaper. The rough surface will prematurely wear the bushing, sprocket, chain, and other parts of your Kart. Cleaning all of these areas regularly will prolong both the clutches life, and that of the kart. Preventive maintenance is the secret to prolonging the life of the clutch.

If you find that the drum and sprocket assembly wobbles on the engine shaft, this indicates that the bushing is wearing out. You should buy a replacement bushing before you cause damage to the sprocket or sleeve with steel to steel contact. A worn bushing can also lead to a thrown chain. Replacing the bushing early when you first see a wobble will prevent damage to the clutch.

A visual inspection of the clutch will also let you know what may be going on with the clutch in your application. For example, a clutch with blued shoes will indicate that the clutch is slipping. If the clutch is slipping, a user may want to consider a gear reduction, or a different riding technique. Also changing the tire size will affect the overall gear ratio, if your clutch is slipping try a smaller diameter tire. (Read the riding Tech Tips). If the bushing is blue or purple, again heat is a problem however, the bushing needed to be oiled more often, and should be replaced. The blued bushing is also an indication that the clutch is slipping.

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 inspection. 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 blocks so the rear wheels are not touching the ground. If the wheels do move when the engine is started, turn off the engine and try lubricating the clutch bushing. Give the lube enough time to penetrate the clutch then restart the engine. If the machine continues to take off by itself even after the clutch has been oiled, remove the clutch and perform a visual inspection of the bushing, and the springs that hold the shoes on. If the bushing is blue or purple in color, and or the springs are loose, then replace those parts as needed. If other parts are damaged then the clutch must be replaced.


There is a pretty cool product on the market to provide (In my opinion anyway) a much better way to lube the clutch bushing. (Unfortunately I'm not able to find the link to it at this time.) From what I recall, this product consists of a clutch retention washer & a 'special bolt' that threads into the end of your engines output shaft. This 'special bolt' has been center drilled for the length of the bolt. The head of the bolt has been tapped to receive a Zerk type grease fitting. If I recall correctly... the engines output shaft needs to be modified by drilling a small hole from the outside to the center.

Now when you install the clutch, plus the new retaining bolt & washer. You are able to take your handy dandy grease gun with your favorite grease & give your clutch a nice shot of grease where it needs it the most.

If someone is familiar with this product & knows of a link to it. Please add it to this post or send it to me in a PM.

Here are a few more technical links on centrifugal clutch design, operation & proper maintenance.

Extreme Duty Centrifugal Clutches
Extreme Duty Centrifugal Clutches
Fun Kart

Thank you
~JM~
 
#8
That is a lot of interesting info JM. I found and downloaded the owners manual and it says to also blow it out and lube bearing only. these things are tiny.
 
#9
I also found that a new clutch is $20 so I will replace it and go from there. At least I finally get to replace something on my new toy.
 
#12
MAX Torque makes the "zerk bolt" or Zerkbolt.......max-lube clutch comes with one

how to drill crank
Max Lube

Buy:
Max Lube clutch system 3/4" #35 12 tooth clutch mini bike go kart

Picture of the bolt idea:

Zerk/Bolt Assem For Brister Clutch
Part #: 4-8489

4-8489 - Zerk/Bolt Assem For Brister Clutch | Go Kart & Mini Bike Parts | MFG Supply

Im making my own and modding the bushing to let the grease in....just got bolts and 1/8th Zerks today.....stock clutch on order....

Zerk/bolt Assembly for #7680/7681 Max-lube Clutch $6.92
Amazon
Amazon.com: Zerk/bolt Assembly for #7680/7681 Max-lube Clutch: Patio, Lawn & Garden

Ebay
8489 - ZERK/BOLT ASSEMBLY FOR #7680/7681 MAX-LUBE CLUTCH $7.99
8489 - ZERK/BOLT ASSEMBLY FOR #7680/7681 MAX-LUBE CLUTCH on eBay!


http://www.gokartsupply.com/clutches.htm scroll down....bolt kit available $8.50

these clutches use a 5/16-24 bolt 3/4 long (briggs/ predator 3/4 shaft inside threads) with a zerk in the end and drilled and grooved clutch parts to let the grease flow in place.....pretty neat idea.......

Schools out.........

Jim
 
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