YS FZ70S Operator's Manual

OPERATOR'S MANUAL
FZ70S
Fig.1
Front Nut
Rear nut
FEATURES
The FZ70S is the most powerful 4 cycle engine of its size and was de ­
veloped for sport flying as well as power demanding acrobatics.
• Supercharged system
• Fuel injected
• Regulated and pressurized fuel system
• Muffler
The pressurized fuel and injection system makes throttle response supe­
rior and is unaffected by tank level.
GLOW PLUG
Select the most appropriate plug from those designed specifically for 4
cycle engines. Glow plug selection greatly affects the maximum engine
output and low idle. We recommend the YS #4.
INSTALLATION
I.
Connect the engine to the tank as shown in fig.1. Since high pres
sure is applied to the tank, tighten all connections carefully. Care
must be taken to prevent pressure leakage due to under tightening of
the check valve or by kinking the fuel lines.
2. Always use a fuel filter. We recommend the YS fuel filter.
3. Match the direction of the check valve arrow fl9.1 with the arrow fac
ing to wards the tank.
SPECIFICATIONS
Bore 27.7mm
19.0mm Stroke
455g·
Weight (engine)
(muffler)
33g
2,OOO-15,OOOrpm Practical RPM
Tube
Fuel Filter
PROPELLER INSTALLATION
Due to the high torque of the FZ63 engine, we have equipped it with a
double lock system for safety.
1. Mount the propeller and tighten the rear nut. Next, tighten the front
nut as shown in Fig.1.
2. Select a good quality propeller that will turn in the 9,000 to 12,000
rpm range. We recommend sizes 12x8, 13x7.
STARTUP
1. Remove tube B from the filter: remove tube Afrom the check valve,
then fill the tank. (CAUTION: If tank is filled or under pressure re
move tube Afirst, then tube B. Fuel will eject if tube B is removed
while the tank is pressurized. )
2. Open the needle valve 2 turns from the fully closed position.
3. Open the throttle about 10% from the idle position ( not fully). And
tum the propeller 10 times. This primes sending fuel to the carbure
tor.
4. Close the throttle to the idle position and connect the glow plug bat
tery. The engine is now ready for starting.
DO NOT ATIEMPT TO START FULL THROTILE,
AS THIS IS VERY DANGEROUS.