I'm working on a friend's Craftsman rider with the 22 hp Intek. Initial condition: no crank, with just a click. Okay, no problem. I checked the battery. It appeared charged, but I topped it off anyway. Same click. It's a strong click. I can feel it in the seat...like the starter is actually engaging with the flywheel but it just won't turn it. So I thought I'd check to make sure the engine isn't actually locked. It was. Well, not locked TIGHT, but it took a slight effort then broke free. After that, it started and ran like a champ. I started and stopped it many times after that with no problems. So it's not a sticky/dead spot on the starter motor itself...but in the engine somewhere. I have to believe that this is something that happened when he last shut it down. I'll try it again in a few more days to see if it sticks again. Is there anything he can do to keep this from happening again? Is there anything that I, as his mechanic, can do to reduce the possibility of it happening on him again? Seafoam the cylinders? Methinks that it's got to be a fluke thing...how do you lock up an engine that is used regularly tight enough that the starter can't turn it but easy enough where it easily breaks free with a wrench and runs like a top right after?