Valve Adjustment ?

[legend29]

I had work done on my scooter and it runs better than it ever has before,purr's like a kitten. the mechanic said bring it back after 300 miles to have valves adjusted and it's close to the 300 miles now,So my question is,Do I really need it adjusted if it runs great ? This place has a bad reputation for ripping people off or so i've heard. I found this out after the fact but they did a good job on my scooter so I'm not sure what to do.If i'm supposed to have them adjusted after 300 miles i will.I just want to make sure it's legit and i'm not being scammed for money.