We’ve been talking about ignition systems and their repair, but one important component is flywheel removal. Especially if you have a dotted engine. Usually the points are under the steering wheel and when they go bad, the steering wheel must be removed.
You’ll find that steering wheels have illusionary retention devices, particularly fast-rewind systems that include ball bearings.
You’ll also find that once you figure out how to remove the “fast rewind gear system”, the flywheel is fixed quite tightly on the crankshaft.
This article is about:
– How to remove the “fast rewind gear system” in the first place.
– Second, how to remove the stubborn steering wheel.
– And finally, how to put it all back together.
It should be noted that the steering wheel has ends on it. If any of these fins break, the motor will become unbalanced and vibrate severely. If the fins are broken, the flywheel is junk, so be very careful around the fins.
To remove the “fast rewind tooth”, use a socket wrench and screwdriver. The pipe wrench is placed on the “fast rewind tooth” and the screwdriver is inserted between the cast iron fins. (Note: there are aluminum fins, please stay away from them, they will break)
Rotate the crankshaft so that the screwdriver is pressed against an immovable object. Another method that is more forgiving is to place a piece of wood (this works best when the engine is mounted to the engine mounts on the go kart) under the steering wheel. This acts like a wedge brake.
Gently press down on the pipe wrench. Excessive force is not needed here. The “fast rewind tooth” usually comes out pretty easily then.
A note regarding the “rewind gear”: Unless you like chasing ball bearings all over the floor, keep in mind that a screen usually covers the rewind. Remove the screen, BUT put the retaining screws back in place right away. This makes the “rewind gear” stay attached and also accessible to the pipe wrench.
The flywheel is then jammed onto the crankshaft with a press fit. The flywheel is actually press fit using a tapered shaft opening in the crankshaft. The object is to “pop” the press fit. To do this, a shock usually needs to be introduced into the system.
There are two methods that work best. First hit the end of the crankshaft with a piece of very hard wood and a mallet. Note: Do not use steel on steel, the end of the crankshaft will be crushed and unusable. Repair is usually not possible.
There are tools available that sit on the end of the crankshaft, but even these can damage the crankshaft. So be careful to use minimal crank shocks. And in case I didn’t clarify, the knocks are normal, or perpendicular, or axial to the crankshaft, not to the side of the crank, but to the end of it.
Sometimes that doesn’t work. If the engine has been sitting for years or is more than 10 years old, the crank may have partially rusted away on the flywheel.
Use some penetrating oil on flywheel, crankshaft interface.
Then pry up the back of the steering wheel, very carefully and evenly with a flathead screwdriver or even a pry bar. Very light action is needed. If you are curling with the screwdriver, something is wrong. (something else is holding the steering wheel!)
The flyer should “jump” right away, so make sure you catch it before it flies off and hits the ground. I suggest having a capture system like rags or cardboard.
To reinstall the steering wheel, reassemble it the same way it was disassembled. Use the pipe wrench and screwdriver method to tighten the “rewind gear”.
Again, don’t over-tighten the “rewind gear”. Also note that the washer was put back in place.
Just as a side note, the only real reason a flywheel should be removed on modern magneto style engines is if the key shorts. If the key was sheared, you need to look at other areas of the engine for damage…