Trolling motor on a pontoon boat

I found a 2005 Power Drive with 70# of thrust, for a good price. It was in good shape and everything worked.
Of course it uses a 24V battery set up, so by using some scrap treated plywood, I made a raised base for the 24 series batteries, under my console. 
This allowed me to secure the batteries and keep any water from pooling. After adding a smart, dual bank charger and an exterior plug, I have a nice functioning trolling set up.
The 70 pounds of thrust moves this pontoon very well, even in a river’s current. I am quite happy with it and I don’t think I would be as happy with a 55# thrust.

Pimply I agree on weight but also take in consideration the canopy.

When sizing a trolling motor for a pontoon boat take into account the weight as was previously mentioned, add to that a pontoon will also catch more wind and wave action force than a boat of similar weight. Under sizing a trolling motor will leave you frustrated especially if you fish often in less than perfect conditions.

"Boat weight is the most important consideration to take into account when choosing a trolling motor. A beginning rule of thumb is that you want a minimum of 2 lbs of thrust for every 100lbs. For example, if you have a 3000lb boat, fully loaded, then the calculation is (3000/100) * 2 = 60lbs of thrust."

So, a 55# trolling motor would work on up to a 2700 lb vessel.