I don't flip mowers like the OP is describing. Those go in the back for spare parts. One can have a great looking mower that runs half arse. And one that doesn't look so good, that's in tip top shape, with a ton of new parts on it. But people will buy the good looking one over the ugly one, almost every time.
Flipping mowers is a money maker for me. Simply because I don't put too much money and time into them. They're used with no warranty, other than I give them a break on the labor if something does go wrong with them after the purchase. (which I don't tell the customer they're getting a break)
None the less. Back to the subject:
These mowers that come in that the customer describes as an easy fix, many times turn into tar babies. It's one thing after another. Especially Troybilts and Craftsman mowers. I've got one in here now that started out just changing the battery and replacing the fuse and fuse plug. Has ended up with those things plus, 2 drive idlers, deck belt, blades and deck idler. Carburetor, heat shield, fuel lines, filter and shut off valves, linkage bushings for the carburetor, flywheel key, resealed valve cover & new cable ends.
Each time I find something, you gotta call customer to find out if they wanna pay for the repairs.
This customer is tired of me calling. I'm tired of calling. But like the tar baby it is, I just can't seem to get rid of it. Last night, when moving it around back, the rear end started whining.