Not trying to offend you, but please, use the search function. This has been asked a thousand times.
The widest you can go on that rim is apparently 150, over that, rim change is needed. Also described a thousand times.

 

Sorry. Didnt mesn to bother you. New to the bike world and this web site.

 

No worries, bud!
Welcome to the forum!

I think you're gonna like this bike a lot. I know I love mine.

Maybe you could stop by again and post a pic or something. We love to see pics of these old girls.