If you take a lawn mower or other small engine to a repair shop the hourly rate is around $40.00 to $50.00 per hour depending on who you take the small engine or lawn mower to.
Some lawn mower repair shops charge more per hour than others but you can expect to pay between $40.00 to $50.00 per hour for small engine or lawn mower repair.
Part of that cost is for overhead costs and the rest which is usually $15.00 to $18.00 per hour goes to the small engine mechanic doing the actual repairs.
In most cases for a cheaper push mower it's not really worth the cost to have it repaired by a repair shop as the cost of repairs including the parts and labor costs can add up to more than the cost of a new push mower itself.