i agree that there is a 'gap' in the available motors.

i'm sure the bean counters have a reason ... if there was a market there would be a motor available.

It was those bean counters that decided it would be cheaper to make the 4 HP out of the 6 HP rather than have a special frame size for the four. I guess they were hoping nobody would notice that it weighed the same as the six. My 4 HP really is 47 lbs. dry, honest! I spent a lot of time looking for the lightest four-stroke I could find that had a remote fuel tank and at the time that was it at 47 lbs.

Quick phrase: Electric motor, batteries in place of water ballast and small solar panel to keep batteries topped up.

Unfortunately the reality is a small solar panel will not be able to keep up with what the electric motor will be using especially on a long haul. I hope I live long enough to see that as a possibility but presently the range and power of electric can not even come close to what I've got with the 4 HP Yamaha and it's 3 gallon tank. John Welsford estimated I have a range of about 60 miles without refueling.

LEHR propane fueled outboard, 2.5 or 5 HP. is a possible solution as can use remote bottle.

You'd think Honda would offer the 2 HP with a fuel pump and a remote tank if they had 1/2 a clue as to what us small boaters need. If it could be retro-fitted to the older motors, then they'd really have something.

The LEHR 2.5 sounds interesting especially since the propane could fuel the grill too. Catch a fish and throw it on the grill is something I'd like to try.

My 4 HP Yamaha is definitely more than the SCAMP needs power-wise but it was already paid for and the reserve horsepower is only "reserve" until you need it. It's not too difficult for me to imagine circumstances when the extra power will be welcome. I live on the Intercoastal Waterway just south of St. Augustine and a fun trip for me would be to motor and/or sail down to Daytona and back. I could easily carry enough fuel in one or two tanks to do that even if the wind decided not to blow that weekend.

propane on a boat scares me more than liquid gas. would feel more comfortable about the LEHR if a tank could be fitting that correctly drains overboard and all the hoses don't enter any bilge space(s).

problem ... the logical location is on the transom which is where you don't want the weight.

small boats require a lot of compromises.

On the FL 120 I got to test my little trolling motor I had installed on Scamp. It is a salt water 24 volt, 63 # thrust electric trolling motor. I bought it on closeout at the Bass Pro Shop as a rebuilt factory motor.

We lost our wind and were battling the currents, tide and waves on the FL 120 this year on three of the four days. We ran the motor for close to five hours total. It never slowed down an 1/3 throttle. When I got home it still had over 12 1/2 volts in each battery when I got home.

Mike Monies' The Red Scamp

Re concerns/fear of propane in boats. Storage tanks for marine use are available, and tank refilled at your local propane dealer site. Tank can be located as needed and is attached to engine by a single hose which can be made to desired length. There is only one hose, and that is the supply from tank to engine. Leak-check at time of hooking-up tank to hose can be accomplished with a solution of liquid soap, a little sugar (for better bubbles), and water. No vent required as propane is a compressed gas, self-delivering to the engine without the use of a pump...
Now on to a slightly different tack, seems there may be another option for using propane. Looks like there are a number of sites online that deal with propane conversions for small engines.

a propane canister, or any compressed heavier than air gas, needs to be in a locker than is 100% sealed from the boat. the locker must be above the waterline and have an overboard vent at the bottom that does not terminate below the waterline.

any feed hose that goes to a propane devise must exit the 'locker' using a vapor-tight thru-bulkhead fitting.

some sources -

http://www.westmarine.com/webapp/wcs/st ... ne-Systems

http://www.pcmarinesurveys.com/Propane% ... lation.htm