Why do I have to prime my lawn mower?

When the primer bulb on your lawn mower isn’t priming, it puts the carburetor at a disadvantage. Designed to replace air in the fuel lines and carburetor with gasoline when you depress the button several times, a primer bulb provides a crucial service that makes starting the engine easier.

How do you fix a lawn mower that does not start?

Your Mower Won’t Start:

1. Loose, Dirty or Disconnected Spark Plug in Your Lawn Mower: Check it out, clean off debris, re-connect and tighten.
2. Dirty Air Filter: Clean or replace.
3. Fuel Not Reaching the Engine: Tap the side of the carburetor to help the flow of gas. If this doesn’t work, you might need a new fuel filter.

Do all lawn mowers have a primer?

Your new lawnmower has an automatic choke system. You don’t need a primer. The engine should start with a few pulls of the rope.

How do you start a lawn mower with primer?

How to Prime a Lawnmower Carburetor

1. Remove the cap from the lawnmower fuel tank.
2. Locate the primer bulb on the side of the lawnmower engine.
3. Press and release the primer bulb three times with your finger to prime the lawnmower carburetor.
4. Pull the throttle lever on the lawnmower handle to the “fast” position.

What happens if you over prime a lawn mower?

When a lawnmower has been sitting unused, the gasoline gradually drains out of the carburetor, and when the carburetor is dry, the machine won’t start. Most lawnmowers have a priming button that sprays gas into the carburetor, but if you overdo it, you’ll upset the gas/air balance and flood the engine.

What happens when you prime an engine too much?

If you prime too much, you have too much fuel for the amount of air in the cylinder, and the fuel won’t ignite. When you attempt to start the engine, this excess fuel might be splashed by the piston. Eventually, this splashing fuel creates a smaller fuel-to-air ratio and BOOM, it ignites.