Re: how to change pitch from 19 to 21(prop)where in nc
Take it to your local marina. They send it out to a prop shop. They get a discount from the prop shop so the cost is usually the same as you would pay by sending it direct to the shop.
If you have no one close, look up Atlantic Propellors in Maryland.
Prop shops vary in their expertise and quality of their work. Some prop shops are not equipped or will not re-pitch a propellor so ask your marina to check before sending out the prop. If you cannot see an example of the quality of their work, you would probably be more satisfied buying a used 21 pitch prop. At lease you can see what you are getting.
However, cupping the prop will give the effect of a 2 pitch increase on engine rpm. This assumes your prop is not already cupped.
Check ebay. Search "outboard motors." I think I saw a used force prop there