Loosening the Fan
To keep the fan in place (see the fastenfan tip)
you need some loctite. Unfortunately that makes it extremely hard to get
the fan off. The only way I know to loosen blue loctite is to heat it up, but
how to do that with a plastic fan?
Recently I thought out the following trick, after I could not even get
the fan off using pliers, and it works for me!
Degrease the outside of the fan, and put some double sided tape on the aluminium part.
This allows you to gripe the outside of the fan firmly with pliers, without causing
too much damage. Lock the crankshaft with a piston locktool or with a toothbrush
in the carb hole (NOT the exhaust port!)
Put a few millimeter of water in the 'cup' at the top of the fan, so that the crank shaft
just sicks out of the water. Then use a pencil torch (see my decarbonizing tip).
Aim the torch at the tip of the crank shaft sticking out of the water.
Heat it up until the water just starts boiling (and not longer).
The water should prevent the fan becoming hotter than 100°C while the
loctite significantly weakens at that point.
Use the pliers to turn off the fan (hopefully).