View Full Version : how do i build a boat motor with a lawn more engine


jchronister3468
08-07-2005, 11:42 PM
hello everyone i need some help. i would like to know an enexspenisve way to buld a boat motor with a lawn mower engine im going put it on a home made 14 ft jon boat any sugggestians would be appreiated with this.thank you jerry

yokebutt
08-08-2005, 12:02 AM
Jerry,

Most expedient way is probably to graft the engine on to the lower end of a discarded outboard.

Yoke.

gonzo
08-08-2005, 12:54 AM
The most inexpensive way is to get a used outboard. Look into an old SEARS/Ted Williams motor. They had Tecumseh motors. They were also very heavy for the power.

Thunderhead19
08-10-2005, 01:03 AM
inexpensive way.....Make a sleeve out of pipe, and use it to add..I dunno say six feet of shaft to the motor. Get a piece of plywood with a hole in it (for the shaft) and mount the motor on it. Put a prop on the end of the shaft, fix the damned thing at an appropriate angle and mount the whole show into a rudder post. Now you have steering and trim. I saw this mostrosity on a documentary on...some...Polanesian..islander fishing ..environmental...something.

Ranger
08-14-2005, 12:01 AM
Take a look at http://www.go-devil.com/

It isn't exactly what you want but you can get an idea from it. In this case, the (horizontal shaft) motor would sit above the transom and the shaft/prop extend well back. The other choice is to run it through a stuffing box and out the underside of the boat. In the first example, you tilt the motor up to start it, then put it in the water. In the second, you have no clutch and you are fighting water resistance in order to start it.

One problem you never will actually solve is prop angle; it's going to be tilted the best you can do.

lewisboats
08-14-2005, 09:41 AM
inexpensive way.....Make a sleeve out of pipe, and use it to add..I dunno say six feet of shaft to the motor. Get a piece of plywood with a hole in it (for the shaft) and mount the motor on it. Put a prop on the end of the shaft, fix the damned thing at an appropriate angle and mount the whole show into a rudder post. Now you have steering and trim. I saw this mostrosity on a documentary on...some...Polanesian..islander fishing ..environmental...something.

Sounds like a 'Dragontail Motor'. The most likely example that comes to mind is in the Bond movie 'man with the golden gun'. He runs the canals of Bankok I believe.
Should be an easy build with a horizontal shaft motor.

Steve

Bighillwill
08-14-2005, 10:38 AM
If you tilt a vertical shaft mower engine very far, the splasher for the oiling doesn't work right. These engines don't run with actual oil pressure, just a splasher inside the case. running it on a tilt for very long will usually trash your engine.

If you can find a horizontal shaft motor, like from a rototiller, it would be better.

Thunderhead19
08-14-2005, 07:29 PM
.....not to mention the carburetor. The oil situation assumes a "wet sump" motor, ie: a four stroke. I used to have a Lawn Boy mower that had a two stroke "dry sump" motor. It was light and powerfull and had quite a small power head....until I blew it up....

longliner45
12-30-2005, 11:12 PM
briggs straton are now making a boat motor with 5 hp 8hp or so .it is a lawn mower engine .they have worked the bugs out .and seem pretty cool probably be just as cheap to buy one new from them. dont know the web site .should be easy to find

george allard
02-28-2006, 07:51 PM
I have seen a lot of boats powered by Briggs and Stratton engines in the Reelfoot Lake area in north west Tennessee. They are all inboard mounts and used in the stumpy lake. They have a protected prop that never hits anything. Search for Reelfoot Lake on the internet.

Richard Hillsid
03-28-2006, 02:50 AM
Found this image. War time Finland.

Wellydeckhand
03-28-2006, 04:21 AM
inexpensive way.....Make a sleeve out of pipe, and use it to add..I dunno say six feet of shaft to the motor. Get a piece of plywood with a hole in it (for the shaft) and mount the motor on it. Put a prop on the end of the shaft, fix the damned thing at an appropriate angle and mount the whole show into a rudder post. Now you have steering and trim. I saw this mostrosity on a documentary on...some...Polanesian..islander fishing ..environmental...something.

Yahama, Robin and alot other brands sell this prop. Indonesia is graet user of such machine in rivers....... although do not suitable for sea..... beware.

The engine range from 3 mono- 24 Hp V machine can take from kerosen or gas run water emergency pump. The shaft act as a ratio kit that manage the propellar at the end side.

Useful but sound terrible as the noise in term of dB would make your nearest neighbour complaint.

Wellydeckhand
03-28-2006, 04:27 AM
briggs straton are now making a boat motor with 5 hp 8hp or so .it is a lawn mower engine .they have worked the bugs out .and seem pretty cool probably be just as cheap to buy one new from them. dont know the web site .should be easy to find

I prefer 2 stroke than 4 stroke because it is lighter but in Thailand I have seen they use small car engine with the pole.............;)

1ghandi
07-14-2006, 02:09 AM
You need to set it up like the fishermen a Phuket Thailand do , same design as the Go-Devil , you will need the 2stroke engine about 6hp min also change the carb the LM carbs are too crude , I have bought Mikuni carbs for mine .
.....................................Cheers Ghandi

View Full Version : how do i build a boat motor with a lawn more engine