FUJI-IMVAC BT24M Operator’s Manual

Operator’s Manual for BT-24M

SPECIFICATIONS

Displacement: 1.45 cu in [23.9cc]
Horsepower: 3.0hp [2.18kw]
Ignition Style: Spring-Assisted

Recoil Starter

R.P.M.: 4000 - 12,000rpm
Fuel: Gas/2-cycle engine oil
Weight w/Muffler: 3.13 lbs [1.4kg]

Manufactured by FUJI-IMVAC INC.

YOKOHAMA, 235-0005 JAPAN

Worldwide Distributor (except Japan): Hobbico, Inc.

Champaign, IL 61826 USA

www.fuji-imvac.com

Fuji-Imvac is not related to the original Fuji Engines sold by Mecoa.

SAFETY TIPS AND WARNINGS

Always use a balanced prop. An unbalanced prop will cause high levels of

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vibration that may be harmful to your driveshaft and engine.

Be sure to keep your driveshaft well lubricated. Failure to do so may cause vibrations

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that can be harmful to the engine. Re-lubricate your driveshaft every 2-3 runs.

Keep foreign objects away from the propeller. Never start the engine on loose

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gravel or sand.
Keep onlookers away from the running engine, especially small children.

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Do not attempt to stop the engine by throwing anything into the path of the

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propeller or by grabbing the driveshaft.
Make sure the fuel line is well-secured to the engine and to the fuel tank so that

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it won’t come off while in use.
Do not use silicone fuel line because it will be attacked by the gasoline. Use

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vinyl or neoprene rubber fuel line.
Always secure the fuel line away from the cylinder head. The engine’s heat can

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damage the fuel line.
Muffler pressure to the fuel tank is not required.

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Never touch the engine or exhaust system after a run. Parts of the engine and

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exhaust will be hot and may burn you.

Before transporting your model, remove all of the gasoline from the tank and lines.

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Always use high quality oil intended for 2-cycle engines.

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Use only low-octane, alcohol-free gasoline. The carburetor diaphragm will

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gradually deteriorate if you use gasoline with alcohol. You will need to replace
the diaphragm in about 80 hours of operation if you use gasoline with alcohol.
Do not install your throttle servo inside the engine compartment. Doing so could

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cause radio interference. Install all electronic radio devices at least 12" [305mm]
away from the engine.
If you are not planning to run your engine for more than a month, drain the fuel

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tank and remove any fuel from inside the carburetor. Do this by running the
engine at idle until it quits by running out of fuel. Keeping gasoline inside the
carburetor over an extended period of time will damage the diaphragm valve
and clog passages inside the carburetor.
Because the carburetor is more complicated than those used in glow engines,

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keep the fuel clean by using a fuel filter. Use a filter intended to be used with
gasoline engines. Metal filters intended for glow engines are too coarse and will
not screen out finer particles.
If you intend to run this engine on an engine stand, or on any other rigid mount,

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use hard rubber isolation mounts. The crankcase and other parts of the engine
may crack if you do not provide some kind of vibration absorption mechanism.

Do not operate the engine in a closed room or where ventilation is not adequate.

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Gasoline is extremely flammable. Keep it away from an open flame, excessive

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heat or sources of sparks. Do not smoke or allow anyone else to smoke near
the engine or the fuel tank.
This engine was designed for use in model boats. Do not attempt to use it for

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any other purpose.

PREPARING THE ENGINE

1. Check to see that all screws and bolts are tight. Check carefully for any cracks,
broken or missing parts. Tighten or replace before proceeding.

2. Install the spark plug in the cylinder head.

SPARK PLUG

The recommended spark plug is a Champion RCJ-6Y. To avoid improper operation
or possible engine damage, do not use any other type of spark plugs. The plug gap
should be 0.016" to 0.024" [0.4mm to 0.6mm]. If the plug gap is incorrect, adjust it
with a spark plug gapping tool, wash it with gasoline and allow it to dry completely
before you reinstall the plug in the engine.

INSTALLING THE FUJI-IMVAC BT-24M IN YOUR BOAT

Note: The Fuji-Imvac BT-24M must be installed onto mounting rails which are then
mounted to your hull’s mounting lugs. Use hard rubber isolation mounts between the
mounting rails and lugs. The instructions listed here describe a typical gas boat
installation and do not necessarily apply to all makes and models. It is a good idea to
consult your hull manufacturer’s instruction manual for proper mounting procedure.

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1. Place the BT-24M on your boat’s mounting rails. Mark and drill the engine

mounting bolt holes on the mounting rails.

2. Fasten the engine onto mounting rails using four 4mm socket head cap screws
and four 4mm lock washers. It is a good idea to use some threadlocking
compound, such as Great Planes® Pro™ Threadlocker (GPMR6060), on the
screws.

3. Install the engine and mounting assembly into your boat. (Consult the manual
that came with your hull for proper mounting position)

4. Attach the fuel line to the carburetor. It is a good idea to use a retaining clip to
hold the line in place. Use only gasoline-safe fuel line. One line should go to the
carburetor and the other is to be used as a vent. You can fill the tank by using
the carburetor line as fill line if you have access to it or install a third line to be
used as fill line.

5. Install the throttle servo at least 12" [305mm] away from the engine. Make sure
that you get the carburetor’s full range of rotation with your servo travel.

6. Attach the water cooling lines to the cylinder head.

Optional:

7. Mount a kill switch in a secure manner inside the engine compartment. Make
sure that it is easily accessible and away from engine components that may
be hot.

BEFORE OPERATION

Go through the safety tips and warnings at the beginning of this manual to

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ensure a successful and safe engine run.

Prepare only the amount of gasoline needed. Aged gasoline could damage the

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engine and cause it to overheat.

If the engine was just run, make sure you allow enough time for it to cool down

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before you run it again. It is important to clean up any excess fuel that may have
leaked inside the hull.

Check to see that there are no foreign objects in the path of the propeller. Secure

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any loose articles of clothing so they cannot be drawn into the propeller.

Fill the boat’s fuel tank with the adequate gasoline mix.

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BREAK IN THE ENGINE

To break-in your BT-24M, you need to run the engine for about an hour with a fuel
mixture that contains a 25:1 (4% oil) fuel/oil ratio. The engine’s output power will
increase gradually over the first few tanks.

Do not adjust the high-speed needle on the carburetor to break in the engine. If you

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do so, carbon will accumulate in the spark plug and that will make ignition difficult.
Do not run at full power for extended periods of time while breaking in your engine.

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Make sure that the engine has adequate cooling.

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