You'll have to set it out front with a for sale sign on it, and wait! Also put a price on it. If its too much, nobody will stop. If its too cheap, it'll go quickly!
If the price is reasonable, anybody who stops, you will have to haggle the price with them!
Clean it all up nicely, and make it look good, and it'll sell.
I've sold stuff from $25 to $300. If it is clean and looks nice, starts right up, makes no clanky or funny noises, doesn't smoke, or leak oil, it'll sell. Ya make the price seem like ya want to retire in Florida--you'll be mowing yer own lawn with it!

Thanks for the words of wisdom they will be much heeded. On that note I'm also looking for some helpful hints on acquiring a replacement 21HP engine for my Husqvarna riding mower. It decided to break a rod on me last summer and have been told that it is cheaper and easier to replace rather than rebuild. Thanks again

is the 21 HP engine a twin cylinder and if it is would you sell the broken 21 HP engine