I'd say about 12 to 14 hundred miles or so.
You mentioned Richards as being reliable for parts. IIRC during ther time that I had my friends Gravely in my shop working on it, IIRC it was Richards in West Virginia that he purchased a supposedly good serviceable cylinder from. It was supposedly bored out to .010" over, and have new guides etc in it. He ordered it and the piston and rings to fit this freshly redone cylinder. From the start it smoked really bad and no amount of running for break in made any difference on oil consumption. It would literally suck a crankcase of oil out in about 10 minutes flat. I pulled the cylinder off and gave it a good going over. The darn cylinder was bored on a taper, so much that when the piston was in the downside of the stroke, the inner edges of the piston rings would be visible. I called Richards up, and they denied that they would send out a cylinder such as that. We then took the old cylinder and had it bored to fit the new piston, and it worked pretty fair, but it really should have been bored even larger in diameter, as it did not quite clean up enough, but at least now it would run and not suck out oil in a matter of minutes.
My friend did not want to fool around with this Gravely anyhow, and only wanted to get it running so he could sell it. It was given to him as payment for some welding he did for a fellow. He spent all weekend welding various items around his farm, and when it came time to get paid the fellow simply said he never paid for labor in cash and only bartered etc for it. So my friend left with the Gravely and all its accessories for his days wages...........He was only a yongin at the time right out of trade school. The Gravely and accessories were just setting in the yard for years until he finally moved them from his fathers house after his father died, and decided he would try it for his grass cutting jobs around his new house, which he soon found out a small cheap push type mower was a lot quicker. Now his wife wants it all gone and so does he.
