In the air breather; it is 'best' to put a very small amount into the foam or paper filter. The air breather is located in different places depending on the type of engine on the mower, you will have to look around a little bit to find it I believe.
The air intake .
I'd suggest a lawn mower motor
You don't. Starter fluid is a really good way to damage the motor inside because it created far more pressure than the motor is designed for. It's best to find and fix the problem rather than use the fluid. You would put starter fluid in the gas tank.
You have to remove the left side headlight bulb. With the bulb out, use a hose and funnel to put the starter fluid into the headlight cavity, then put the bulb back in. Be careful not to add too much starter fluid as excess may leak out and is considered to be an environmental hazard.
no
By connect a starter motor backwards I assume you mean put the negative cable where the positive cable would go and then put the positive cable to the negative connection. In that case the starter motor should run backwards. That might be a handy thing to do if you are using a starter motor to power something else such as a winch or maybe a pump.
No. Put in power steering fluid.
Directly into the carburetor throat (remove air cleaner).
Automatic transmission fluid.
You can spray starter fluid directly into the air intake. You can also remove the cover to the air filter and spray it directly into the air filter.
What type of fluid?
Usually lack of oil or somebody put something in the gas.