I'm looking for an outboard for a Grumman Sportboat. the original owner Andy Renzetti used an older Mercury 15hp that weighed about 86lbs. I asked him how it ran with the 15 and he just smiled and "its tippy" The guys a peice of work... Anyway, I found a Johnson Commercial 6.5 on *bay that looks to be in real good condition and it states that it's a Commercial. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=300299658462 What's heavy duty about the "Commercial" engines? I've also noticed that some are "Belgin Made" like the Evinrude Delux. The boats rated for a 7hp as its a little older and Andy has added a front and rear deck with hatches as he is a Fly fisherman. I need help trying to decide what to power the boat with.