Just the fact that he did not do a compression test FIRST before any other work
tells you he does not know what he is doing.
When any shop gets a unknown bike the first step is a compression test.
A check of the basic health of the engine. If that is acceptable, THEN the cam chain tension
is taken up and the valves adjusted.
All issues must be resolved before looking into the carbs.
Shops that I have worked at call that a complete work up and all unknown or new bikes
brought into the shop get a complete work up.
The only bikes that do not get that is when a customer says a horn does not work.
Tires and other suspension system problems. Or brakes
Or the customer says a cable needs adjustment ,something not involving the engine.
Get away from that guy as fast as possible. Serious.
On a Roadstar Adventure.