I recently purchased a Hero Maestro (Dec 26 2018). So far it has gone for two services. The layout of the workshop is such that the bikes are taken to a slightly far of place where access is unauthorized for non employees. I can only stay at a distance and observe what's being done to the bike.

I have referred to the user manual that enlists the schedule and activities of each service. I strongly feel they do not do everything on the list. However, I don't really have any 'ammo' to question them as I can't even see what exactly the mechanic is doing.

Just wanted to know how you'll deal with such instances. How can one be sure that the servicing done was up to the mark and there's nothing to worry about. Most of my friends say they just "trust" the machine and go with how the bike feels. I still feel that's not sufficient as some problems might not show up instantly but lead to bigger problems later. For example, I would rather clean the air filter even if there's less accumulation instead of waiting for it to build up and do more damage before being cleaned. I fear the mechanic sometimes feels it's not even necessary to check the air filter given the bike is hardly used.