I agree that valve clearances are likely not correctly set and frankly if your mechanic can not do that job I would worry about the rest of the work. Set stone cold spark plugs out by using the tappet depression tool one at a time after using a syringe to remove the excess oil. You obviously measure first with feeler gauges looking for 0.40mm inlet and 0.45mm exhaust clearances. The Haynes Beta Manual tells you how, but you need a decent stock of shims to replace those note the right size. Avoid shims smaller than 3.50mm to prevent cam damage. If you have saved shims from previous engines you probably have lots of 4.20mm! Note always measure the shim thickness with a decent digital vernier or micrometer. to check the actual size and never use shims with heat bluing or surface scuffing.
Good luck.
Eric
I took some measurements on the exhaust side. the first cylinder is at 0.50, 2, 3 and 4 have difficulty reaching 0.30........
I will see if I can obtain the special tool somewhere in the Netherlands.
It's a shame about the three hours of work the technician put into this.
-Gerke
