by Barnacle Bill » Sat Mar 05, 2005 2:16 am
I had the same question and ended up here. While Mr.Knight is correct I have an example of a specific case.
Mercury 3.5hp outboard. Called Mercury and they use a conversion factor of 70 lb thrust = 1 hp.
This may not apply to everything but it tells me I need a huge trolling motor if I want to replace my outboard which weighs 30lbs.