Over the last two months we have discussed the ins and outs of ignition systems. Being able to service your ignition system is a critical step in being prepared in the shop. There are not many tools required to service the ignition system on 4- cycle racing engines, but this is one you can’t live without if you have any plans of doing your own engine work. A proper flywheel puller is the only correct and safe way to remove a flywheel from your race engine. Without using the recommended tool, you risk the chance of damaging the flywheel which could lead to a potential reliability issue.
There are a couple types of flywheel pullers available to the racer. Some types of pullers, like pulley pullers, are not an approved method for removing the flywheel. This type of puller can physically damage the flywheel. This is no different than changing a tire with pliers; sooner or later it may come off, but not with out severe damage to your equipment. If the right tool is used, the nuts can be used over again without worry of them being stripped out the next time. Removing a flywheel is much the same; the proper puller for the job will make the task easy and ensure that the job is done right.
Briggs and Stratton now offers two types of pullers for their racing engines: the older two bolt style that utilizes the fan mounting bolts on the Animal flywheel or the two specific puller holes on the World Formula’s flywheel, and the new center pulling puller available for the new PVL flywheel. The older Animal flywheel puller can still be used on the new PVL flywheel; unfortunately the new PVL puller will not work on other flywheels.
The older puller uses the holes in the flywheel to pull off of. The center of the puller is supported against the flywheel nut once the nut has been loosened and backed off a couple of threads. The bolts from the puller are turned into the flywheel a sufficient amount for positive engagement. The nuts on the bolts are then turned evenly towards the flywheel, working back and forth between the two. Once the force of the puller becomes sufficient the flywheel will come off with a pop. The nut, still on the crankshaft, will keep the flywheel from coming completely off. Once loose, the puller and flywheel nut can be removed followed by the flywheel. This procedure is the same for the World Formula cast iron flywheel, but the puller is physically smaller because the bolt centers are closer together.
No matter what engine you are working on, always consult the service manual for the proper steps to removing the flywheel.