Sherri,
Big, fat deposits when they bring them in helps. Get enough too cover at least the cost of the mechanics time and parts.
If the machine turns out too be junk (Cost of repair exceeds value of new.) Then at least you get them too come back too pick up thier deposit money and make the decision on what they want done with it. (Take it or toss it.)
Some people get indignant about it.....and insist that you already have thier valuable property as collateral. (Remind them that a lawnmower store doesnt need another lawnmower.) Show them your junkpile behind the shop.
When we get the "gotta have it guy", my people up front know that they have too check with me before they do anything. I run a service history check on my computer in the shop. We keep pretty tight records and notes on our customers. We have a special code for certain situations. The "PIA" code tells me that we have someone special up front. I send those customers down the road too a competitor. (Our competitors do the same...so there is no net loss of customer base.)
Have the clause on the work order....."If not picked up in 30 days, the machine gets put into a big crusher on day 31." We make them sign it. That motivates some.
If they still dont "get it"......Get Chris a big ol' bottle Screech and goad him into making some nasty phone calls late Saturday night or early Sunday morning. You should see a line up at the store on Monday morning.
BCS Tractor & snowblower