4. Holes in the fuel line. The tear resistance of silicon tubing
is very low and it’s not uncommon to develop a hole where the
fuel line is assembled over the edges of brass tubing. If the
engine runs well on the first half of tank and then quits, it’s
almost always caused by a hole in the pick up line inside the
tank. Look for bubbles in the fuel line while the engine is run-
ning, this is a sign of holes somewhere in line.
5. Pressure tap in muffler plugged or restricted. Some fuels
contain oil that can collect on the interior of the muffler and
plug off the pressure tap causing the fuel tank to loose pres-
sure and starve the engine for fuel. This will cause the engine
to run lean then rich then lean. Try running the engine with the
pressure line removed from the muffler to see if the problem
still exists.
MAINTENANCE
When you are finished running for the day, run your engine dry
by removing the fuel line at a moderate speed or allow the fuel
tank to run dry. It is best to squirt some K&B AFTER RUN OIL
in the carburetor, then flip the propeller about 10 to 20 times.
This oil will keep castor based fuels from gumming and protect
internal engine parts from rust and corrosion. When storing
your model between running sessions, it is best to wrap your
engine in a rag or plastic to prevent dust, dirt and moisture
from entering the engine. The engine should also be wrapped
in a rag between running sessions at the pond.
CHECK TIGHTNESS OF ALL SCREWS
On a regular basis you should check all screws associated
with the engine. Mounting, head, back cover, muffler, prop, lower
unit, etc. These screws must be properly torqued and not over-
tightened. Always use a cross torquing technique as mentioned
below.
BEARING CARE
Your engine operates in an aquatic environment and uses fu-
els which attract moisture which will shorten the life of the
bearings if not cared for properly.
A cleaning hole is provided in the front housing to aid in clean-
ing the front (or top) bearing. Simply place the spout tube of
WD40 (or similar product) up to the hole in the housing and
“back-flush” the bearing until you see fresh lube coming out
from under the flywheel. The bearing may also be oiled with
K&B After Run Oil using this same procedure. Do not use
WD40 (or similar product) on the lower unit.
FLEX SHAFT CARE
An access hole is provided in the lower unit for pre operation
lubrication of the flex shaft. We recommend that each time,
before you run the engine, you lube the cable with a mixture of
50% STP & 50% 20-50 weight oil. In addition, we recommend
that you periodically remove, inspect, and re-lube the entire
flex cable with K&B # 8449 shaft lube or equivalent for maxi-
mum cable life.
FUEL & CLEANLINESS
Always use fresh, clean fuel to prevent starting problems and
poor engine performance. We recommend that you use a fuel
filter in the line between the tank and the needle valve assem-
bly. A filter will prevent foreign material from reaching the car-
buretor and causing a clog.
The engine will accelerate from idle to full throttle smoothly
and instantaneously when properly adjusted. The engine may
not idle well at a low setting or accelerate as quickly until it is
broken in.
BREAK-IN
1. BREAK-IN running should be done at a slightly rich setting.
The needle valve should be set at a point just into this range
from a four cycle setting. Run the boat in the water at maxi-
mum throttle for 2 minutes, then throttle back for approximately
30 seconds. Repeat this sequence until approximately 30 min-
utes of accumulated running time has been obtained. AVOID
MAXIMUM THROTTLE FOR LONG PERIODS OF TIME DUR-
ING BREAK IN and AVOID RUNNING FOR LESS THAN 5
MINUTE RUNS.
2. After the first 30~45 minutes, run the engine at a normal
peak needle valve setting. This should be a little on the rich
side to ensure engine received proper lubrication.
BOAT INSTALLATION
The engine must be mounted firmly to the transom of the boat
using the machine screws and plate supplied with the engine.
Never use wood screws to mount the engine.
Care should be taken to the mounting position as recommended
by the boat manufacturer.
TROUBLE SHOOTING
Generally most engine starting problems can be traced to bad
glow plugs, weak starting batteries, or inadequate fuel sys-
tems.
GLOW PLUGS
The glow plug when connected to a 1.5 volt battery should
glow a bright orange. If the plug slightly glows the battery or
plug should be replaced.
If the seal leaks around the center plug post, replace it.
The glow plug element should be examined after several flights.
If the element is deformed or touching the side of the plug
body, replace it. If the glow plug element is pitted or has a
frosty look, the engine is running too lean and continued run-
ning will seriously harm the engine.
FUEL SYSTEMS
The most frequent problems encountered with fuel systems
are:
1. Improper fuel tank location. The fuel tank should be located
as close to the engine as possible.
2. Fuel pick up in tank is not free or in the wrong location. If
the boat runs rich, then lean, then rich, the pick up may be
picking up air, then fuel, then air, as the thrust of the engine
causes the fuel to be forced from the front of the tank to the
back.
3. Dirt or contaminates in the fuel, tank, lines, filter or carbure-
tor. Many times a sliver of fuel line or other debris will cause
the needle orifices to become plugged intermittently so a con-
sistent mixture setting can not be obtained. Careful inspection
and cleaning of these passages will usually solve the problem.
Don't use silicone sealant on areas of the carburetor that in-
volve fuel passages.
