Translated (sort of) from the original Russian by Bill Weller 7-4-07. My notes are in blue.
The original site is here: http://iv70.narod.ru/IV/9/GD.htmlThese weedeater (brushcutter) type motors are made so cheaply that I would not put a lot of money or effort into this project. On the other hand though, used ones abound, and repair parts are reasonably priced.
I do not have the original authors name. Nor does there does not seem to be a copyright or date. My apologies to the author for borrowing it, but I thought this a significant project well worth translating.
You can see my conversion HERE
And my DIY aluminum prop for it HERE A suitable prop is an absolute necessity.
I found another Russian version HERE
The
most commonly available motor is the "Salute", which does not
approach practicality on all parameters and suited only as an Anchor.
The initiator of our movement of "Lawn-mowers" became
Radchenko Sergey Mihajlovich (for the M 494 Catamaran)
which
seems to be a prop attached to a petrol weed trimmer. Having
looked at their products, and having seen the variations and reviews, I
now understand what is necessary. The weed trimmer completely
answers all my requirement.
I acquired a petrol powered Weedwhacker.
Model
N.358.795543 of Firm CRAFTSMAN (manufacture of the USA)
Engine:
duple [2 cycle],
volume 25cc / 1,5 cubic inches.
Capacity: [fuel]
approximately .700 liters. [23.6
ounces US]
Weight: 4,5 kilo. [9.9 pounds. This is
heaver than the FL-25 at 6.5 pounds]
Alterations of a mower were reduced to:
Shorten the shaft.
First
remove the reel by removing the regular nut (2). It resembles a long
tube with a female thread.
Attention. Be
careful not to lose the
nuts, as they are a unique thread!!! Not metric and not inch.
Shortening the original flex shaft: The flexible shaft core resembles a super heavy duty speedometer cable. The ends are square and fit into a matching holes on the motor and cutter drive. Do not use a hacksaw to cut it. The steel is hard enough to ruin a blade. Use an abrasive cut-off wheel. The end can be flattened square by hammering so it will be accepted by the the upper socket in the motor. It won't be pretty, but will work. After you have a usable core, cut the plastic inner guide and the outer tube to match the length.
Making a prop.
Step of the screw [pitch] is approximately 10mm ., that is if, to put a plate on a table it is necessary to unbend the blade on height 10mm, then to unbend the second blade. The screw is easy to adjust. If turns not high it is possible to cut blades or to adjust a step of the screw, with preliminary the screw a nut (2) and strong enough keeps. If the prop hits something, the motor simply stops.
Attention: it is possible and is necessary to make a ring nozzle [prop spinner] to protect the screw threads.
Throttle control.
The original throttle control
has been thrown out. Instead, I have bought a bicycle gearshift
and
mounted it on the case. And still: in the future I plan to change the
direction of release.
[This appears to be similar to the Weedeater Featherlite FL-25]
Fastening
of a shaft to the motor.
It is made from 20mm. The
laminated plywood two overlays which fasten to a head of the motor and
four screws clamp the shaft. The shaft can be removed for transport.
Results
of operation:
The
motor was used one season, all summer long, on
Saturdays-revivals, and one campaign to Ladoga (25 days). During this
time
it burnt 15½ L.
92
octane gasoline. The engine requires a mix of gasoline to oil
1:40 [should be
oil to gasoline ratio of 1:40] .
Further it is
possible to reduce gasoline oil ratio to 1:100. I
checked
up
and does not affect the condition of the motor. [I would NOT advise that]
On one
tank during a calm, it is possible to travel about 10 km. [6.2 miles, 33.6 miles to
the gallon]
Speed under weedeater power (it was
measured using a GPS):
The
Catamaran of type "Open space" in weight of 120 kg. [265 pounds],
during a calm,
with one person on board - 7,9 km/h [4.9 mph]. A
catamaran of type "Open space"
in
weight of 120 kg. With one person and gear on board + a catamaran
"Albatross" 5,6 km/h. [Some other boat]
With one person on board and gear - 7 km/h. [4.35mph]
Malfunctions. The motor works
for hours at a time. It always starts on the second pull.
After burning 5
litres of fuel, the recoil starter cord failed to retract. The case was
opened and the spring tightened. After that, the "starter" worked
trouble-free.
After a
campaign to Ladoga in the motor there was extraneous noise. Opening has
shown, that as a result of the bolts loosening the rod became
loose. The rod has been replaced. I recommend, to avoid similar, after
burning 5 litres of gasoline to make sure the bolts are
tight. [The FL-25
does not have the bolts he mentions]
Others who have converted these little engines to outboards have said the exhaust is very quite if you run a tube into the water. On the Featherlite FL-25 and its various versions, the muffler is attached to the cylinder with 2 strong springs. It would be simple to adapt a tube since the hole in the cylinder is round.The FL-25 is made SO cheaply, it has part of the crankcase made of plastic held on by four screws. The next model change (Featherlite FX 265) they only used only TWO screws and even more plastic parts. There was a FX-25 (heavy duty) and an earlier model FL-23 that is heavier. Also made was a 15cc, a 19cc version, and many others.
I found this in the original HTML as a note, but have no idea if it is valid. spm111@yandex.ru There seems to be no copyright, date, or authors name.
