Lawn Mower Extras
All modern lawn mowers have what is called a ‘dead man’s lever’ which basically means you have to squeeze it to enable the engine to run. Let it go to say empty the bag and the engine stops. This is a safety feature to prevent numpties trying to clear a grass blockage with their hands whilst the mower blade is still doing a zillion miles an hour. This can dent the blade!!!!
If you need a petrol lawn mower and don’t wish to keep pulling the starter cord you can have electric start (ES) or what is called a blade brake clutch (BBS). This latter feature stops the blade but doesn’t stop the engine.
Cylinder mowers often have removable blade cassettes so that you can 
swap perhaps five blades for nine blades or insert a spiking, raking or scarifying attachment. This is an excellent way of getting several machines in one if a cylinder mower is suitable for you. However, it is principally a lawn mower so don’t expect it to do other jobs as well as a dedicated lawn aerator or scarifier.
For rotary lawn mowers a spare blade is a great idea. The one rotary blade does a lot of work so a fresh or sharpened blade twice a year is a 
good idea if the mower is used more than an hour per week. You can sharpen the blades yourself quite easily by using a ‘balancing and sharpening’ kit available from most DIY and lawn mower suppliers.
