General servicing like oil, filters and plugs if petrol you could do yourself,
easier than riding a bike.
Engine, most mechanics could sort
Pump, any pressure washer repairer,
Heat exchanger, depending what was the problem, a fabricator, welder.
My hx split and my mate re-welded it, i gave him 4 bottles of real ale and 40 toilet rolls
Not a lot else to go wrong, depending which machine you go for.
A lot of lawnmower repairs are quite handy to know, specially if it has a Briggs engine.
I am hopeless at electrics and find my tm easier to sort.
They dont go wrong that often, and great work horses. make life easier.
Andrew