It all depends on your state. Most states require a minor to take a motorcycle course prior to taking the written and riding test to get a motorcycle endorsement on his drivers license. He will want to do that rather than just riding without the endorsement which can get him ticketed and also make insurance not pay any claims if he is involved in an accident. Size wise, yes the Grom will be a fun bike for him even if he is taller and heavy. For a first bike, sometime's it's best to not have too much power. Mischief will ensue! Ha.