Hello..I have a small 11 foot fishing boat that I use in lakes in Colorado. I currently have 2 electric motors and want to buy a small outboard for it. It is rated for a 15 hp motor, but I'm thinking about a 6 to 9.9 (I have to take it off and carry it when I am done). Any ideas on what the best engine would be ?? 2 stroke or 4 stroke ?? We do a lot of trolling. The boat only weighs about 150 pounds. Thanks for the input !!