hi guys! I recently picked up a home made 13hp surface drive, I thought the price was to good to be true but it looked like a good quality build. Well it didn't take long to figure out why it was priced the way it was.
The pulleys and belt are to small for the torque.
I'm thinking, replace the pulleys with 1" wide timing pulleys. My question is, is a 1" wide gates belt adequate and how many teeth should I have for the top and bottom pulleys.
Thanks in advance for your input!!!

Tight lines and shoot straight!

Worked on a 18 Hp SB Briggs which had a 32T upper and a 50T lower pulley On a Mudbuddy. If you could find a 27-30T upper and use a 50T lower you might be able to get it to work, with a smaller dia. and pitch prop. BPS offers different gear sets in their catalog, might give them a call, also maybe suggest a belt.