background image

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.

Tube C in FIG.1
Use the soft silicon tube ( inter  3mm, outer 5mm ).

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 Mount

Rear Mount

Battrery (4.8~8.4V)

Switch

Red

Black

Ignition Box

Tube A

Brown Black Yellow

Black

Red Black

Plug Cap Screw

Break-in Needle

Tube C

* Please tap lightly with a small hammer,

  as the spark plug cap is tight fit to the

  spark plug.

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 a good quality alcohol based model engine fuel containing 5% to  
     25% nitro, and oil content 5% to 25%. Do 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 DZ185CDI 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 20x10.5, 20.5x10, 21X10. 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.

Break in needle

Open break-in needle half turn in counter clockwise direction while 
break-in. After break-in, close it to 1/6 turn or fully closed position. By 
this procedure, fuel flows into crankcase through  break-in needle. It 
makes lubrication better and also prevents percolation (vapor rock) . 
We recommend to open it a little under high tempreture in summer time. 
NOTE: Engine power decrease as break-in needle open. When you 
need maximum power, close the needle fully.

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

DZ185cdi RED

 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

Reviews: