18
ENGINE CARE AND MAINTENANCE
As noted above, foreign matter in the fuel used may cause
malfunctioning of the pump and/ or carburetor. Be sure
to use a high quality fuel filter between the refuelling
can and fuel tank. The O.S. Super Filter (L) is available
as an optional extra part. The Super Filter (L) is fitted
inside the fuel can at the outlet and has a special double
filter element to ensure that the fuel tank is always
supplied with clean fuel.
Be sure to check the carburetor at least once every 30
flights. Remove the needle- valve holder from the
carburetor, using the appropriate open-ended wrench, and
extract any foreign matter that may have lodged in the
threaded part of the carburetor body. Minute particles of
foreign matter may upset mixture strength, so that engine
performance becomes erratic and unreliable. Remember
that obstruction to fuel flow may also cause the engine
to become overheated, resulting in internal damage.
If, after use, the fuel system is left unattended for a lengthy
period, there will be a tendency for the methanol content
of the fuel to evaporate sufficiently for the oil content to
"gum" the internal parts of the pump. Therefore, it is
advisable, at the end of the day's flying, to empty the
fuel-tank, invert the engine and pump out the remaining
fuel in the system by rotating the propeller until no more
fuel is ejected from the carburetor. If the pump is not in
use for a while (more than one month), remove the pump
and wash out its interior by injecting methanol through
the " IN" nipple. Fit the sealing cap (provided) to the
nipples, after draining out the methanol.
Note :
Kerosene will cause swelling and rapid deterioration
of the fuel tubing. Do not, therefore, use kerosene
for cleaning this engine.
At the end of each operating session, drain out any fuel
that may remain in the fuel tank.
Next, energize the glowplug and try to restart the engine to
burn off any fuel that may remain inside the engine. Re-
peat this procedure until the engine fails to fire. Remove
the glowplug and eject any residue by rotating the engine
with an electric starter for 4 to 5 seconds while the engine
is still warm.
Finally, inject some corrosion inhibiting after-run oil into the
engine. Rotate the engine a few times by hand, to make
sure that it is free, and then with an electric starter for 4 to
5 seconds to distribute the oil to all the working parts.
Do not inject corrosion inhibiting after-run oil into the
carburetor as this may cause the O-ring inside the car-
buretor to deteriorate.
These procedures will reduce the risk of starting difficulties
and of internal corrosion after a period of storage.
Note:
19
29015019
27681340
22681953
27881330
29481300
29481100
27881800
27881810
27881820
29481600
29481200
27881400
N.+M3X6
No.
1
2
3
3-1
4
5
6
7
8
9
3-2
3-3
Carburetor Gasket
Mixture Control Valve Stop Screw
Fuel Inlet
Mixture Control Screw
Rotor Stopper
Carburetor Body
"Ｏ"
Ring(S) (2pcs.)
"Ｏ"
Ring(L) (2pcs.)
"Ｏ"
Ring (2pcs.)
Mixture Control Valve Assembly
Carburetor Rotor
Throttle Lever Assembly
Description
Code No.
The specifications are subject to alteration for improvement without notice.
70A CARBURETOR EXPLODED VIEW & PARTS LIST
Type of screw
C...Cap Screw M...Oval Fillister-Head Screw
F...Flat Head Screw N...Round Head Screw S...Set Screw
1
2
3
3-1
3-2
3-3
4
5
6
7
8
9
20
C
.M
3.
5x
18
C
.M
4x
10
1
3
2
4
5
6
7
8
9
10
11
12
13
11-
1
14
15
16
17
18
18-
1
18-
2
18-
3
18-4
18-
5
18-
6
18-
7
18-
9
18-
8
19
Type of screw
C...Cap Screw M...Oval Fillister-Head Screw
F...Flat Head Screw N...Round Head Screw S...Set Screw
ENGINE EXPLODED
VIEW
