It's been a few months since I've had the time to post on MOTHER EARTH NEWS about the propane mower experiment that I began back in August of this year. I'm happy to report that the plans, as written, stand — and that I have experienced NO problems with the propane mower throughout a busy summer of mowing the grass on at least a weekly basis.
Many people have asked me about fuel consumption. I have a roughly 6,000 square foot lot. Now, some of this is taken up by the footprint of the house, but in general, I can mow the entire yard two to three times on a single 1 pound bottle of propane, without any issue whatsoever. My grass doesn't grow terribly fast, as there are a lot of trees, but as mentioned I am mowing at least once a week. I've consumed about three or four bottles of propane since the summer began. This does not count the bottle or two that I used in testing and tweaking the mower to get it to where it was when I wrote the plans.
Since it is now December, and starting to get cold, I've been preparing the propane mower for the off season. I've sold a number of sets of the conversion plans, and had a number of people give me interesting feedback on the conversion process. Most people are not using the plans to convert their lawn mower — most seem to want to convert generators, which are a great candidate for the propane conversion, and even a few smaller engines, like two stroke motors, which will not work because there is no oil sump in a two stroke engine to provide lubrication.
To prepare the propane mower for the winter, all I really had to do was bring it inside. I removed the spark plug, and sprayed a light penetrating oil, like WD-40, into the spark plug hole, then pulled the pull start a few times to cycle the piston in the bore. After that, I replaced the spark plug and changed the engine oil. Once this is done, the mower will be fine to sit for any length of time without worrying about the fuel gumming up in the carburetor. This is much simpler than my old gasoline lawnmowers, where I had to either empty the fuel tanks, or run them out of fuel, before storing them to insure that they would start reliaibly the following year.
If you are interested in converting your own lawnmower to propane, or if you have questions or want to purchase a set of the plans for yourself, you can either follow the link to my Ebay auction: http://cgi.ebay.com/Propane-Lawnmower-and-Small-Engine-Conversion-Plans-/320588013025?pt=LH_DefaultDomain_0&hash=item4aa488dde1
Or just email me: derekjsherwood@NOSPAM.yahoo.com (remove the NOSPAM). I look forward to hearing from anyone who wants to undertake this project.