I'm thinking of purchasing a 81 sportster never owned a bike before is this a good year and model of bike?

 

Nothing wrong with them, other than the frame design only lasted 3 years, '79-'81. That means that rear fenders, seats, gas tanks, etc. are pretty specific to those years, so older ones and newer ones won't fit if you need to change anything out.

 

A greater concern is simply that the bike is 33 years old and it's condition could be anything between excellent and a near basket case! So when looking at it take a friend who knows bikes and can give you a second pair of eyes, while checking it over. Check the dates on the tyres, which will give you an indication of how well it has been looked after, also alert you to an expense if they are over six years old.