What are the advantages and disadvantages of masturbating 3-4 times a week for 15-17 year old male?

It's natural: No major advantages or disadvantages and it is perfectly natural to do. The only down side, may be embarrassment if your friends or your parents walk in on you.

Nothing specific: Masturbation is a normal part of human exiatance.Some cultures frown on the process ; most seldom discuss it openly. If anyone does so to the exclusion of interacting with people ; pursuing age ; peer related activities, it can interfere with normal emotional growth, as any preoccupation might. For most, it is simply part of their life.