Talkback: How to maintain your lawn mower

A friend of mine has had a petrol lawnmower for 6 years and was wondering why it constantly sounded like it was going to cut out....turns out it's never been serviced, no oil check,no nothing, so this was a very useful feature I've emailed him the link

OK, so far so good for owners of petrol mowers.
Please would you do an equivalent maintenance guide for those thousands of us with hover mowers.
Thanks!