HOW TO INSTALL AN ARC FLYWHEEL on a Clone Kart Motor. From ARC Racing and Kart Tech Facebook Group.

Over the years we have received calls from time to time regarding one of our flywheels slipped or "spun" on the shaft. We have them explain the step by step procedure on how they installed the flywheel and 9 out of 10 times some part of the installation was not done properly. I'm not going to sit here and blame you, me or the man on the moon for engine or part failures, but I will show you how we recommend installing a 6619 Billet flywheel on a Clone engine. This will be the same for all flywheels we sell. Each step will have a photo and they should be in order.

Step 1. After removing the stock flywheel remove the flywheel key using a pair of standard side cutting pliers. 

Step 2. Apply some medium grit grinding compound to the taper area on the shaft. Just a few dabs is enough.


Step 3. Mate the flywheel with the crank shaft and twist it back and forth while applying slight pressure inward on the flywheel. Twist it 15 to 20 or so times and rotate the flywheel 90 degrees and twist 15 to 20 more and repeat this several times. Do not go crazy with this step, all you are trying to accomplish is preparing the mating surfaces of the crank and flywheel. This can be done while the crank is in the engine, I just used a crank and flywheel to get good photos for your viewing pleasure. 

Step 4. Using a good cleaner such as carb or brake cleaner, clean the tapers of the crank and flywheel very good including the key slot. You can use a Q-tip for the slot. After using the cleaner take a dry paper towel and wipe the tapers again to see if any residue appears. If residue appears re-clean, if not inspect the flywheel and crank taper for continuous contact. You will see a darkening in and on the tapers.

Step 5 If you are using a offset flywheel key be sure to install it correctly. This is one of the main causes of flywheel slippage. If you notice photo #5 you will see that the key is running parallel to the crank shaft and not the taper. If the key is running with the taper the back side of the key could stick up too far and hinder the two tapers from mating properly resulting in a spun flywheel every time. There is absolutely no reason to run a key if the above steps are followed properly. The responsibility of a flywheel key is to align the flywheel and hold it in the proper position until it is torqued down. This will mate the flywheel taper to the crank taper and create a very tight bond. The key holds nothing after that... Period.

Step 6. This photo is a reference to show where the coil should fire and how you should line the coil on the leading edge of the magnet. This is something important to check using a timing light pointed directly at the coil because we have seen some coils fire slightly different than others.

I will set my timing before I install the cylinder head. This way I can use a dial indicator to find TDC and the degree wheel to set my timing, but the piston stop/degree wheel method is just as good.
After you achieve your desired timing setting torque the flywheel nut to 65-70ft lbs. Some people use more but I do not recommend using less with the exception of using a 6602 ultralight flywheel. Torque it no more than 55-60ft lbs. ***Lock tight is not needed if the above steps are followed correctly***

We hope this sheds some light on how to install one of our Billet flywheels. This technique is recommended for the solid (Non Adjustable) Billet flywheels as well as the adjustable flywheels with the steel center hubs. If you have any questions or concerns on this or any other procedure call us toll free at 800-521-3560.