What size prop for outboard mercury?

I have a 1985 25hp xd mercury outboard. Its a 2 stroke and a tiller handle. Recently just got it for my boat and its needing a prop. What diameter and pitch would this motor need?? Ive googled and had no luck. Somebody please help!!!
Answers

Bubba Gubbins

Use Mercury Marine's prop selector tool. http://legacy.qsprops.com/prop-selector/#

JetDoc

Ask a local Mercury outboard engine dealer.

fuzzy

what size & pitch prop depends on what type of hull you put it on & how you intends to use it. Either of the other answers will give you what you need.

Pecker Man

Do you mix geritol with the gas?