Minimoto Garage - Clutch Shoe Replacement

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Step by Step
Clutch Shoe Replacement
Step by step pictures and instructions listed below. (Note: The pictures listed below are of a GRC GP Racing Pocketbike with a Polini 6.2hp water-cooled engine, but the basic setup is the same on all Pocketbikes.)
Step 1.
Make sure you order the right clutch shoes for your Pocketbike. Here is a picture of the Polini clutch kit showing the Polini part number. This is the 2 shoe clutch replacement kit.

Step 2.
Open the clutch kit and make sure all the parts there for the install.

Step 3.
Locate the clutch on the left hand side of the Pocketbike, you may have remove the plastic depending on which type of Pocketbike.

Step 4.
Remove the chain guard and any other piece that will be in the way of the clutch drum removal. The clutch drum has 4 bolts holding it to the engine. The bolts are located in each corner of the drum. Once you remove the bolts you can simply pull the drum loose, which will give the necessary slack to remove the chain off of the sprocket.

Step 5.
Place the drum and bolts out of the way for now, so that you can work on removing the clutch shoes. The rubber belt that you see to the left is the water pump belt that must be reinstalled once the drum is reassembled.

Step 6.
Remove each of the clutch shoes by first removing the bolt located on the shoe. After removing the bolt you now have to take off each snap ring by pulling it apart or by prying it outward with a small flat head screwdriver. The new clutch shoes come with new snap rings, so don't worry about damaging the old ones. The clutch springs can be removed by just pulling them outwards away from the bike.

Step 7.
Now that you have the old clutch shoes removed you can take the time and clean any trash or debris that may be in the clutch housing.

Step 8.
Here is a picture of some clutch shoes that came apart while under heavy stress. The clutch shoe on the right is missing about half of the surface plate.

Step 9.
Install each of the clutch shoes by placing the clutch shoe bolt through the hole on the end of the clutch shoe after lining up the spring rod inside so that the bolt goes through the loop at the end of the spring rod. Once you line it up, tighten it firmly, but not so tight that you can't get it off next time. Repeat the process for the other clutch shoe. Next install a new snap rings and washers on each of the clutch shoes. It is best if you have some fine needle nose pliers to insert into the holes of the snap rings in order to stretch it and slip it over the post into the locked position.

Step 10.
The picture below is showing the new clutch shoes after installation. Be sure to inspect the washers and snap rings so you don't leave any pieces out. The picture does not show the spring holders on each side of the clutch springs, which need to be installed as well. You will have to tighten the bolts at the end of the springs in order to adjust the engagement of the clutch. If the springs are loose, the clutch will engage too soon. The rpm's will not be high enough to produce power causing the bike bog down at the start. If the springs are too tight, the clutch will engage too late and will create a bad stall while trying to take off from a dead stop. The clutch adjustment is a trial and error process and you may not get it right the first time, so be patient.

Step 11.
Now you're ready to reinstall the clutch drum and tighten all your bolts back down. Be careful not to leave any steps out and be sure you don't end up with extra bolts.

Warning! If your pocket bike is water cooled, be sure you've reinstalled the water pump drive belt. Failure to do so will cause the engine to overheat and seize.

Finished now you're ready to ride.
Thanks again to Mid-South Minimoto for this great how-to!
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