Flywheel puller (universal)

A universal flywheel puller is an essential tool when working on scooter or motorcycle engines.

An important note about "universal"

Although these tools are sold as "universal", they are not all the same. Flywheel pullers differ in two main parameters:

1. Thread size (diameter): The most common sizes are M24x1.0, M26x1.0, M27x1.0, M28x1.0, etc.

2. Thread direction: Most have a right-hand thread, but some (e.g. certain older Minarelli or Piaggio models) may have a left-hand thread.

Before using the tool, always check the thread on your scooter's rotor with a caliper or by screwing in a bolt of the right pitch.

How to remove the flywheel safely

1. Attaching: Screw the flywheel puller into the centre of the rotor. Important: screw the tool in by hand as far as possible to use the full length of the thread. If you only engage a few threads, you can strip the thread out of the flywheel itself and ruin the rotor for good.

2. Holding: Hold the body of the puller with a spanner so that it doesn't turn.

3. Pressing: Turn the puller's centre bolt (the pusher) until you feel strong resistance.

4. Releasing: Once the bolt is bearing on the crankshaft, keep turning it. You will often hear a loud "pop" – this means the flywheel has come free of the crankshaft taper.

Safety and technical tips

• No hammer: Never strike the centre of the flywheel with a hammer. The crankshaft is very precisely balanced; impacts can distort it, causing severe engine vibration and rapid bearing wear.

• Cleaning the taper: Before refitting the flywheel, be sure to clean the crankshaft taper and the inside of the flywheel thoroughly with degreaser. If any oil is left there, the flywheel can slip and the shaft can seize.

• Checking the key (locating key): After removing the flywheel, always check the Woodruff key. If it is damaged or worn, it must be replaced with a new one. If the key is not seated tightly, the flywheel can move freely, which will damage both the shaft and the flywheel.

• Watch the thread: If the tool is hard to turn, don't try to force it. This usually means the threads don't match or are dirty. Clean the thread with a wire brush and try again.