Weedeater conversion as primary propulsion?

I see that there is a thread about weedeater conversions that has been running since 2003, but I had some much more general questions about this versus how-to aspects. I have a 14' inflatable boat with a solid wood transom. So far I use it with a 55lb thrust trolling motor but would like to add some range by getting a gas outboard. I don't have a whole lot of cash to spend, otherwise I'd probably just buy a new Honda or Tohatsu 8 or 10 hp motor. Also, I stick to mainly lakes and rivers, many of them very shallow and choked with rocks, logs, and other underwater obstructions. I've already broken my trolling motor bracket twice because the motor hit a log or rock.

I'm currently ordering a new mount/bracket and plan to get that fixed over the winter. The weedeater/mud motors seem to be a good solution for shallow, obstruction-filled water. I'm not really much of a fisherman, more just wanting to get out and enjoy being on the water and I like to do some bird and other wildlife photography when I'm out. My main use for a gas outboard of any type would be to allow me to propel my boat upstream for something like two to three hours, then turn around and head back downstream to my put-in, either partially under power from the outboard, or using the trolling motor and/or oars. For a little more information, my KaBoat weighs about 150lb (boat, trolling motor, and battery), excluding myself (170lb) and any other gear I may carry.

So, my main questions are do folks use these motors as the main propulsion for a boat or just to maneuver around in shallow water occasionally? Also, how about noise? I know a regular weedeater of just about any type is loud as all-get-out. I can't imagine hearing that right behind me for two hours. Can the engines be muffled significantly with any kind of aftermarket mufflers? If I was to use one of these how do they do for range/speed? For the lightweight and packability I might even consider one of these as primary propulsion for using my boat to get out and do some camping on some shallow, scenic rivers, provided it would have the oompf to move the boat and camping gear upstream. Am I living in a dream world to even consider this? Are these motor conversions suitable for what I want to do or am I better off trying to find a cheap, used traditional-type gas outboard? The one thing I keep coming back to is that at least a mud motor type of design would be more resistant to damage in the kinds of rivers and lakes I like to go to whereas a traditional outboard would not be. Finally, here's my boat from a couple seasons back - rigged for a photography outing at a local lake.

 

Seriously? Fifty-eight views so far, and absolutely no one has any opinions on the matter? No one is capable of answering my questions?

 

There is a skeg guard sold as a "river runner prop protector" that helps a normal outboard. It's a plate that keeps the skeg from chipping and goes out to the sides to help pop up the outboard when the prop would otherwise hit a rock on the side or get gravel in the prop.

 

The biggest problems with weedeater conversions are noise and longevity a better solution is a vertical shaft lawnmower engine on an outboard leg but unless you run the exhaust underwater they are still noisy. If I were you I'd stay with the electric trolling motor even if you had to add another battery for more run time or find a small used water cooled outboard. I would still keep the trolling motor mounted for a backup or when you wanted to run really quiet. I have a 12' boat that I run on the Mississippi with a 70 horse merc outboard and a bow mounted 55# thrust trolling motor for emergencies or when I just want to run quiet.

 

Thanks for the input guys. I suspected the weedeater conversions were just going to be too darn loud. I'm out there trying to get photos of birds/otters/beavers/etc. and maybe do some fishing. I don't want to scare away every animal for miles around. I'll keep scouting Craigslist for a good deal on a lightweight watercooled outboard.

 

Your electric motor will run much better with a model aeroplane propeller about 8 inch pitch..more range as it will draw less current for the same speed and if you look on here under electric boats you will find home made collapsable props for these motors...for my larger electric boat I have a petrol engine driving a car alternator and this will keep the trolling motor running all day or until the gas runs out...shaft direct onto the alternator ..no need to gear it up.