Instructions for use

ManualsBrandsSC-ABC ManualsHobbyGlow 7.5cc (.46ci) ABC SC46A-S 2-stroke engine with pot

Force Model Engines have been developed specially to answer the needs of R/C modellers all over the world.

They incorporate a carburettor that has automatic mixture control together with a high silicon content aluminium

piston and aluminium alloy cylinder with a chromed liner.

“Powerful, Reliable High Performance”.

RUNNING IN (Breaking in).

For a long life and high performance every engine needs to be properly “run in” or “broken in” before being put to

full use.

BEFORE CARRYING OUT ANY OF THE PROCEDURES BELOW, YOUR ATTENTION IS DRAWN TO

“SAFETY THE THIRTEEN COMMANDMENTS” AT THE END OF THIS LEAFLET.

The procedure for running in is as follows:

Before installing the engine in a model, beginners are recommended to follow the “test bench running in procedure”

as explained later.

Install the engine in your model and fit a suitable propeller, for example a 9 x 5 or a 10 x 4 depending on the

type of model that the engine is fitted to.

Use a fuel, during the running in period, containing not more than 5% Nitromethane and not less than 20%

Castor oil.

STARTING

Fill the fuel tank with a suitable fuel.

Open the needle valve 2 turns from the fully closed (screwed in) position.

For the next step the “Glow Start Battery” must be DISCONNECTED.

With a finger blocking the carburettor intake, rotate the propeller through three complete revolutions. This

should draw fuel, from the tank, up through the fuel tube and into the engine. Now you can connect the “Glow

start Battery” to the glow plug, this will cause the plug to glow and will assist in starting the engine.

Close the throttle down to the normal idle position. Hold the aircraft firmly and flick the propeller counter

clockwise using a “Chicken stick” or an electric starter. There are various “Chicken sticks” and starting aids

available.

When the engine starts and before opening the throttle fully, it is advisable to move position relative to the

aircraft and to make sure that you are behind the arc of the propeller for your safety.

You should now be able to remove the “Glow start battery” and the engine will continue to run. If the engine

cuts out as soon as the battery is disconnected, turn the main needle valve clockwise ¼ of a turn and start the

engine again following steps 5 – 7 above.

RUNNING IN

For the first few minutes let the engine run with the fuel mixture very rich so that when the throttle is open the

engine is “Four stroking”.

Gradually screw the needle valve in until the engine just breaks into a rich “Two stroke”. At this point stop

turning the needle valve and allow the engine to run until the fuel tank is empty.

Care must be taken not to run the engine in a dusty or gritty environment as foreign matter sucked into the

engine whilst running will dramatically shorten it’s life.

With the needle valve set up as above make 2 or 3 flights. At this stage the engine will still be running slightly

rich and will therefore not be developing full power however there should be enough power to fly your model

unless it is too heavy, too large or the weather is too windy.

It sometimes happens that, due to the position of the fuel tank in the model, the mixture becomes leaner in

flight. If this should happen, close the throttle, land the model and open the needle valve slightly before

continuing with flying.

For the next 3 or 4 flights the needle valve can be very gradually closed to give more power however it is

recommended that the engine is not “leaned right out” and it should be allowed to run just a little rich.

During these early flights avoid manoeuvres such as “top hats” or “stall turns” as these can make the engine

“lean out”. Loops will assist the running in process as they allow the engine to speed up and then run rich again.

After 6 to 10 flights, it should be possible to run the engine continuously at its optimum needle valve setting.

This setting is with the needle valve adjusted ¼ to ½ a turn on the rich side of the position at which the engine

reaches it’s highest speed.

Your engine can be said to be run in when it holds a steady speed at the optimum setting.

Never attempt to lean the engine out to far to obtain a few more revs as this will cause the engine to run too hot

and it may be damaged by overheating.

TEST BENCH (Running in)

Displacement 7.45cc

Output 1.62ps @ 16,000 r.p.m.

Bore 22.0 mm

Practical r.p.m. range 2,000 r.p.m. - 17,000

r.p.m.

Stroke 19.6 mm

Weight 371.5 g

Summary of content (3 pages)

PAGE 1
Displacement 7.45cc Output 1.62ps @ 16,000 r.p.m. Bore 22.0 mm Practical r.p.m. range r.p.m. 2,000 r.p.m. - 17,000 Stroke 19.6 mm Weight 371.5 g Force Model Engines have been developed specially to answer the needs of R/C modellers all over the world. They incorporate a carburettor that has automatic mixture control together with a high silicon content aluminium piston and aluminium alloy cylinder with a chromed liner. “Powerful, Reliable High Performance”. RUNNING IN (Breaking in).
PAGE 2
1. 2. 3. 4. 5. Install the engine in a suitable bench mount. Use a 10 x 6 or 11 x 6 propeller and run the engine for approximately 10 minutes with the needle valve adjusted so the engine is running rich “four stroking”. Close the needle valve until the engine speed picks up and the engine starts to “two stroke”. Allow the engine to run like this for about 30 seconds only and then re-open the needle valve until the engine resumes four stroking. Run for a further 2 minutes.
PAGE 3
SETTING UP NOTE. The high-speed set-up MUST be carried out before the idle speed is adjusted. Settings may change as the engine “Runs in” and may need readjusting after the engine has been run for an hour or so. 1. The main needle valve is used in the same way as on all model engines. It is used for adjusting the high-speed set-up of the engine. Start the engine and with the throttle fully open gradually close the needle valve until the engine is running at its maximum speed.