Tappets Adjustment
1. Tappet clearance is pre-set at the factory.
2. Clearance adjustment may need after one hour of running time due
to initial wear. After adjustment, tappet clearance should be checked
during normal maintenance after every 10 hours of running to main
tain maximum performance.
3. Clearance adjustment should be done when the engine is cool.
4. The proper clearance setting is between 0mm (0.000”) and 0.1mm
(0.004”). The adjustment is achieved by loosening the locknut
(“Fig.2”) and turning the adjustment screw. The engine must be at
top dead center on the compression stroke before any adjustments
are made. This engine runs best with the valves set at a tight
setting. If the valves are set too loose, power will be affected.
Cam Gear Timing
If for some reason you have to disassemble your engine, please follow
these important steps on reassembling the cam gear.
1. Remove the carburetor and back plate assembly. Notice the impres-
sion mark or dot opposite the rod journal on the crankshaft.
2. This mark is to point straight down or lined up with the outer case
seam line at the bottom and hold crankshaft securely.
3. Reinstall the cam with the dot facing you. After you fully installing
cam and then check dot should be pointing straight down will give
you right timing.
Operation of YS Super Mount (Option)
1. It is hold by 4 screws, 2 on the front ring and 2 on the rear soft
mount. There are two different height of spacer we provide.
A set spacer (MN110S) : 10mm thickness
B set spacer (MN111S) : 4mm thickness
2. Please be sure not to hit any part of the fuselage by the engine after
it is installed.
3. If damper oil is leaked, refill TAMIYA damper silicon oil #600.
Damp er is a consumption parts, please exchange if you find worn
or some defect.
Cleaning
This engine uses silicon rubber in many parts. Please use methanol or
model engine fuel for cleaning. Do not use Kerosene, Gasoline, Machine
oil, Automobile parts cleaner or house hold lubricants to clean. It will
harm silicon parts.
Engine Cooling
Be sure to secure cooling air for engine cooling. If it is not enough for the
engine, it causes the regulator and carburetor heat up and makes vapor-
ized or percolates the fuel. It gets deteriorations of engine performance
or stop the engine. Please read carefully below for provision.
1. Please open air intakes and outlets as wide as possible.
2. Take off cowling when you make engine adjustment for a long time.
When air temperature is high, it may heat up the regulator and car-
buretor to make vaporized or percolate the fuel even without cowl-
ing. If it happens, wait till engine well cooling down before you
restart and adjust.
Rusting provision
Do not leave fuel in the engine after the final flight of the day. When you
store the engine long period of time, a few drops (about 1cc) of lubricant
oil must be put into the engine from carburetor and clank several times.
Do not use Automobile engine oil.
57
136.5
14
119.4
68.6
149.5
63
25
58
114
Air
Tube B
Fuel Clunk Tank
Regulator
Front Nut
Rear Nut
Front Ring
Rear Mount
Battery（4.8~8.4V）
Switch
Red
Black
Ignition Box
Brown Red Yellow
Black
Red Black
Plug Cap Screw
* Please tap lightly with a small hammer,
as the spark plug cap is tight fit to the
spark plug.
Tube Ａ
Safety Instructions
In order to use the engine, please read through this instruction manual
carefully. This is a complex,high-performance engine. If you have any
difficulties to understand any part of this instruction manual, please con-
tact the hobby shop from whom you purchased the engine, or contact us
directly.
1. The propeller double locknut assembly supplied with the engine
must be used when mounting the propeller.
2. Always use a good quality propeller and follow the manufacturer’s
instructions.
3. Choose a propeller size that will not allow the engine to exceed the
maximum practical RPM in flight.
4. Always ensure that no people are in front of or beside the propeller
while the engine is running.
5. To start the engine, set the throttle to the idle position and use an
electric starter.
6. After starting the engine, always move behind the propeller to adjust
the needle settings.
7. The engine becomes extremely hot both during and after engine
runs. Do not touch the engine, exhaust header, muffler, or any parts
attached to the engine while it runs or before it has cooled down.
8. If the engine runs incorrectly, DON’T FLY.
9. Do not use this engine for anything other than radio controlled air
planes. Do not use it for radio controlled helicopters.
10. You have full responsibility while you operate the engine. Please be
extra careful for your safety and the safety of others whenever you
operate the engine.
Installation
Connect the engine to the tank and CDI system as in “Fig.1”.
The battery and switch for the CDI unit is not supplied with the engine.
The soft mount and fuel filter are optional.
1. The recommended fuel tank size is 500cc to 700cc (18 to 24 oz).
A standard clunk type fuel tank may be used. If this type of tank is
used, you must use the special clunk supplied with the engine.
Please note that with this clunk, some fuel cannot be drained from
the tank. As soon as any part of the clunk becomes exposed, the
engine will stop due to air entering the fuel pump.
2. Always use a fuel filter. We recommend YS filter (6720). With this fiter,
you must remove the cloth portion of the filter and leave both the
metal filter screens in place.
3. Because of the engine’s pump system,the tank may be placed near
the aircraft’s C.G positrion. The fuel level in the tank will not influence
the engine.
4. Please pay consideration to avoid chafing of the ignition box’s wires
from vibration. Use the plastic “spiral wrap” supplied with the engine
to wrap the shielded plug wire.
5. Please place the ignition box about 15cm away from the receiver.
Some radio components may need to be over 30cm away from
ignition components to avoid interference. Wrap the ignition box in
foam rubber or other vibration absorbing material(in the same man -
ner as the receiver is mounted), and fasten (e.g. using Velcro straps).
Do not use the bracket holes to directly mount the ignition box to the
aircraft.
Fuel
1. Use an alchole based straight fuel ( 0% nitro and 10-20% oil ).
You can
not use gasoline fuel.
2. When filling the tank, disconnect Fuel Tube “A” or Fuel Tube “B”
(Fig.1) for filling, use a stopper on the Fuel Tube “A” to avoid flooding
the engine.
Propeller
1. Due to the high power ooutput of the DZ185 engine, it is supplied
with a double locknut system for added safety. Mount the propeler
and tighten the rear nut, followed by the front nut. The rear nut
has an offset shoulder that the recess of the front nut will secure itself
against.
2. Please check and retighten propeller locknut periodically.
3. Select a propeller that will allow the engine to run at a maximum of
between 6,000 to 8,000 RPM.
4. We recommend sizes 19x11, 20x10.5, 20.5x10. Other propeller
sizes may be used as long as the correct RPM range is maintained.
High Speed Needle Valve Adjustment
1. An electric starter is mandatory for this engine.
2. Turning the needle valve clockwise leans the mixture. Turning it
couner-clockwise richens the mixture. A good starting position for the
high speed needle valve is 1 and 1/2 turns open from the fully closed
postion.
3. To prime the engie, check that the ignition is switched OFF before
turning the engine over with an electric starter (throttle fully open)
4. Close the carburetor to the idle position, turn ignition ON and start
the engine with an electric starter. Run the engine at a high idle RPM
to warm it up.
5. Brake-in the engine with one or two tanks of fuel on the ground, with
good rich mixture setting adjusting for the best high speed needle
position.
6. To achieve best high speed needle valve position, run the engine
with the throttle fully opened. Gradually turn the needle valve
clockwise untill the RPM beginns to drop. The position of the needle
valve corresponding to the maximum engine RPM is referred to as
the peak position. Turn the needle valve counter-clockwose
approximately 1/8 turns from the peak position.
Breake-in
1. Start the engine with high speed needle valve open 1 and 1/2 turns
from the fully closed position and with the throttle at the idle position
2. After starting the engine, increases the RPM gradually by operating
the throttle. Do not suddenly apply full throttle.
3. If the mixture is too rich and the engine misfires, turn the needle
valve clockwise to make the mixture leaner.
4. Breake-in the engine with one or two tanks (600cc or 20oz. tank) of
fuel on the ground, running at the richest possible mixture setting.
Battery for CDI Unit
Use 4.8~8.4V Ni-Cd ,Ni-MH or Li-Po battery with a capacity of around
700mAh. This will be sufficient for 5-10 minutes flights.
Idling adjustment
1. Ideal idling range is between 1,200 and 2,000RPM.
2. When the regulator is turned counter-clockwise, the idle mixture is
leaner. When the regulator is turned clockwise, the idle mixture is
richer. Adjust regulator in 45 degree increments.
3. If idle mixture is too rich, the engine’s RPM will gradually drop and
the engine will eventually stop after continuous idling. Also if
the engine stops when you change the attitude of the airplane on
the ground, the idle mixture is too rich. If the engine’s idle RPM is
unstable during continuous idling, the idle mixture is too lean.
Spark Plug
Use spark plug supplied with the engine. The plug gap should be 0.30mm
(0.013”) and 0.45mm (0.018”). If plug gap become over 0.5mm (0.020”)
, the engine will misfire. If the gap exceeds 0.45mm, tap the element with
a hammer reduce to the gap.
FIG 1
Fig2
DZ185zero
Bore
35mm
Stroke
31.8mm
Weight
965g
（
Engine, Plug
）
100g
（
Ignition Box
）
Displacement 30.6cc
Practical rpm 1,000~9,000rpm
OPERATOR'S MANUAL
Tappet Clearance
