Why

Why?
As if you even need to ask;) Well here are a few of the many benefits.

Pollution:
The motors on a standard gas lawnmower are grossly inefficient, they pollute much more then a car per gallon and many are so out of tune that they make more pollution in a mowing then a car in a week.
Money:
It costs money to keep buying gas, tune ups, and all that hassle, electricity is free with a cheap solar panel. I build mine out of spare parts that you can buy for less then the cost of a new gas, allot less.
Sound:
I hate mowing usually because it is so loud. The sound of a mower going just ruins the relaxation of a weekend. Plus because it is so darned loud, you can't do it at night, or early in the morning, so you are forced to mow in the hottest part of the day! Electric is MUCH more quite. It sounds like a fan more then a mower. So if you want to mow at 1am go for it.
Dependency on oil:
Why depend on others unneededly, they will own you.

Motor:
I used a Subaru starter motor, any Japanese geared style will work. Honda and Toyoda used them allot. They have a stunt wound motor that is hooked up to a small gear box on the side, they are most efficient and easy to modify. I got a good start on how to modify it though instructions on how to make an electric bar stool racer. Check them out in the links section.

What you are basically doing is removing the solenoid, drilling some cooling holes on the top and bottom, and making the shaft stick out. On mine I used washers to hold the shaft out, others welded theirs. I drilled a bunch of cooling holes and instead of welding a fan on to help cool it, I used a Pentium II CPU heat sink and a couple PC fans. They work OK for now, but I would like a better way to cool it. Maybe a better heat sink or a better fan

Battery:
I have not worked this out yet. A car battery "works", but it is not good for long term use, since it is not deep cycle. A 70 amp hour deep cycle will do my lawn about 3 times, but is awfully heavy. Any lead acid is kind of heavy. I have some smaller ones I am going to try next. But in the long run I am going to use NiMH batteries, ether from rechargeable drills or some other source.

The Blade:
I was going to get fancy with this, but in the long run, I decided to hook a pulley to the starter shaft, then hook a regular blade to the pulley. I just drilled 2 holes in the pulley and bolted it on. I lucked out and the depth was the same, you might have to get fancy with the adapter plate to get this right.

Wiring:
I need to put a keyed switch and level meter before I am done. Also, I want to add some more safety with a circuit breaker, and safety switch. I plan on using a pc style plug to hook it to the solar panel for charging.

Solar Panel:
I used a VW solar battery charger. I got it on eBay for $30. Its only about 5 watts, but that is plenty over the week or two time between mowings. I caulked it up and hung it on the side of my garage, when ever I get done, I just hook it up to the battery.

Push lawn mower:
So far I have made a push lawn mower, it is mostly done, and I will share what I have so far with you. It is based off a Subaru starter. I started out with an old lawnmower, and took off the motor.