Yamaha outboard conversion to LPG

I work part time for a bus company. We have a number of propane buses that we acquired as part of a government program. I drive one every day. They get about 4 miles per gallon versus 8 or so for a diesel powered bus. LPG is a clean fuel but not very efficient. For a boat I'd stick with gas or diesel. As for the original post, as other have pointed out the 9 pound tank mentioned is more likely a 90 lb tank. BTW, I use a Yamaha t9.9 on my small cruiser as a trolling motor and slow cruising power source as well At about 4 knots the little Yamaha burns fuel at a rate of 8 miles per gallon.

 

Why Does my Propane Tank Freeze Up? https://www.propanetankstore.com/blog/why-does-my-propane-tank-freeze-up/

It has nothing to do with the freezing point of propane, but rather the boiling point.

A cool, damp climate, like many marine environments creates the ideal condition when other factors are met.

Despite these and other concerns; the use of propane as a cooking fuel even in a boat is almost unbeatable.