Lawn Mower Blades
Lawn mower blades - essential pointers when changing them
Lawn mower blades will not last forever. They will blunt, get bent, chipped, and work themselves loose. If you accidentally strike an obstruction (we all know how easily that can be done), it's best to stop the mower and have a look at your mower blades. Worn and damaged lawn mower blades are a major hazard - they will result in a bad cut, excessive vibrations and poor grass-catching.
Before you embark on changing your lawn mower blades, be sure you have the correct tools and that you fully tighten the blades and nuts when you re-assemble. A blade running at close to 280km/h is dangerous if not held tightly in place.
Always disconnect the spark plug lead BEFORE you fit the new blades on. Replace BOTH blades, not just one - this ensures that you get the right balance in the engine and stops those annoying vibrations that result from mismatched blades. Follow the instructions in the manual (most new blade packs will also have fitting instructions). If you have a 2 stroke engine, you need to stand the mower on its front wheels whilst supporting the handles on a bench. Generally you will need to turn the blade so that it's facing the rear of the chute opening to remove the blade. If you have a 4 stroke lawn mower engine, you need to tip the mower so that the spark plug is facing up otherwise you may end up with the oil draining into the cylinder head and find that you can't start the mower as a result.