OPERATOR'S MANUAL
YS FZ110
FIG.1
Do not attempt to start at full throttle, as this is very dangerous.
FIG.3
BREAK-IN
To maximize engine performance and increase durability, please
follow this break-in procedure:
0.04-0.1mm
52
57 25
120.7
FEATURES
The FZ110 is the most powerful 91 four cycle engine available.
This engine offers many exclusive features that have been proven
on other YS engines.
Supercharged system with simplified structure to keep weight to
a minimum while still retaining maximum efficiency.
Air chamber that uses crankcase pressure coupled with a double
throttle valve system which allows a bigger charge of fuel and air
mixture to enter the intake valve for more power.
Same proven piston design as the 140Limited which creates
more crankcase pressure for a more consistent fuel flow to the
regulator.
Fuel injection system for superior throttle response. This system
is unaffected by tank position or by the attitude of the model.
High Speed Needle
Fuel Filter(YS1195/not included)
Low Speed Needle
Check Valve
Fuel Filter(YS1195/not included)
PROPELLER INSTALLATION
Due to the high torque of the FZ91 engine, we have equipped it
with double locknuts for safety.
1. Mount the propeller and tighten the rear nut. Next, tighten the
2. Select a good quality propeller that will turn in the 8,000 to
FIG.2
GROW PLUG
Select the most appropriate glow plug from those designed
specifically for 4 cycle engines. GLOW plug selection greatly
affects the maximum engine output and low idle. If RPM's decrease
or stop when the booster cord is removed, replace the plug.
We recommend YS #4 (P0040) or OS Type F.
START-UP
1. Remove tube(B)from the filter;remove tube(A)from the check
INSTALLATION
1
. Connect the engine to the tank as shown in fig.1. Since high
pressure is applied to the tank, tighten all connections carefully.
Care must be taken to prevent pressure leakage due to
undertightening of the check valve or by kinking the fuel lines.
2. Always uses a fuel filter. We recommend the YS filter.
3. Match the direction of the check valve arrow to fig.1, with the
arrow facing towards the tank.
2. Open the needle valve 1 1/2 from the fully closed position.
3. Open the throttle fully and slowly turn the propeller ten turn. This
4. Pour several drops of fuel into the carburetor.
5. Close the throttle to the idle position and connect the glow plug
SPECIFICATIONS
Bore 30.4mm
Stroke 24.8mm
Displacement 18cc
Weight 730g
Practical rpm 2,000-13,000rpm
Tube (A)
102.5
Tube (B)
21.5
43
front nut as shown in fig.2.
11,000rpm range. We recommend sizes 13.5~11-13, 14~10-12.
(Diagram)RearNut
(Diagram)FrontNut
valve, then fill the tank.
Caution:If tank is filled or under pressure remove tube(A) first;
then tube(B). Fuel will eject if tube(B)is removed first while the
tank is pressurized.
primes the system by pressurizing the tank and sending fuel to
the carburetor.
cord. The engine is now ready for starting.
1. Use the same size(or slightly smaller) propeller than you intend
to use in flying.
2. Use a good quality fuel which contains 15-20% nitromethane
and an oil content of 15-20%. Synthetic or castor oil can be
used, or a combination of synthetic and caster. Do not use four
cycle fuel due to low oil content.
3. The needle valve should be set so that the engine is running at
a rich setting. Run the engine approximately 20 minutes with this
setting.
4. Mount the engine to the model and fly ten times with this setting.
This concludes the break-in procedure. It is advisable to always
use a slightly rich setting to keep the moving parts lubricated,
even after the break-in period.
TAPPETCLEARANCE
ADJUSTMENT
1. Tappet clearance is factory preset. No adjustment is necessary
2. Clearance adjustment should be done when the engine is cool.
3. The proper clearance setting should be at 0.04-0.1mm. The
HIGH SPEED ADJUSTMENT
1. Adjustment of high speed is done by the carburetor needle
valve. When the needle valve is turned clockwise, the mixture is
leaner. When it is turned counterclockwise, the mixture is richer.
A good starting position for the high speed needle valve is 1 1/2
turns open from fully close position.
2. When the engine is started, open the throttle gradually. Next,
find the peak position(highest RPM) by adjusting the needle
valve. Then the needle valve should be opened approximately
1/8 of a turn from full RPM to achieve best performance. The
engine may stop if the throttle is opened to full immediately after
starting. Wait unit the engine temperature rises and then open
the throttle slowly.
3. For flying, it is advisable to use a slightly richer mixture setting.
By using a richer mixture, the engine temperature is maintained
and RPM stability improves.
LOW SPEED ADJUSTMENT
This engine is equipped with a new low speed needle valve to
adjust the mixture from low to mid throttle. This needle valve is
located on the side of the throttle barrel opposite the throttle
arm(fig.1).
1. Open the low speed needle to 1 1/2 turns from fully closed
position.
2. The low speed needle valve should be set after the high speed
needle valve has been adjusted. Close the throttle gradually to a
idle(approximately 2500rpm). Let it idle for 20 to 30 seconds and
then slowly advance the throttle. The adjustment is satisfactory
at low speed if transition is smooth at this time.
3. If the engine is running rough on idle, the low speed mixture is
rich. If the engine starts to speed up and dies on idle or starts to
detonate, when advancing the throttle, the mixture is lean. Turn
the low speed needle valve clockwise to richen and
counterclockwise for a leaner mixture(note that the direction of
the low speed needle valve is opposite the high speed needle
valve). Adjustments to the low speed needle valve should be 1/8
to 1/4 of a turn increment at a time to achieve smooth throttle
response.
I
MPORTANT! The regulator adjusting screw on this engine is
factory set. No further adjustments are necessary. If for some
reason you have to disassemble the regulator assembly, the
regulator adjusting screw should be set flush with the regulator
body.
DIAPHRAGM AND CHECK VALVE
DISASSEMBLY
Diaphragm:
1. Remove the adjustment screw of the valve, and then remove the
2. Clean the inside with alcohol or appropriate cleaner. Reassemble.
3. Screw in the regulator screw until flush with the diaghragm body.
Check valve:
1. Open the valve by rotating the body counterclockwise.
2. Reassemble the check valve carefully.
IMPORTANT! Silicone rubber is used in many parts of the YS
engine. Use only glow fuel or methanol for cleaning. Gasoline and
other volatile solutions will damage the silicone if used.
WARRANTY
Strict quality control is implemented by our factory in all phases,
from parts manufacturing to final assembly. If performance
deteriorates or a part fails due to a manufacturing error, YS will
repair or replace the engine at no charge.
Should the engine be modified, incorrectly assembled or abused,
there will be a nominal charge for parts and labor. The use of four
cycle fuel due to the low oil content will also void warranty.
unit after 1 hour of operation(includiing break-in period).
When the engine temperature is high, clearance is higher due to
thermal expansion.
adjustment is achieved by loosing the locknut(fig.3) and turning
the adjusting screw.Tighten the locknut after the adjustment is
achieved. After the initial 1 hour adjustment, this procedure
should be performed after every 2 hours of use.
inside valve and spring.
NO. PART# DESCRIPTION QTY
1 F7101 Crankcase 1
F7102A Cylinder Head
2 F7102 Cylinder Head with Liner 1
3 F9103 Intake Valve 1
4 F9104 Exhaust Valve 1
5 F1209 Valve Spring Set 2
6 F9106 Spring Retainer Set 2
7 F9107 Valve Spring Retainers Clips 4
8 F9208 Cylinder Head Gasket 1
9 R6115 Draive Washer Spacer 1
11 F9111 Head Screws 4
12 F9112 Valve Cover 1
13 F9113 Valve Cover Gasket 1
14 F9114 Valve Cover Screws 2
15 F9115 Air Chamber 1
16 F9116 Air Chamber Gasket 1
17 F9117 Air Chamber Screws 4
18 F9118 Air Chamber O Ring 1
19 F9319 Crankshaft 1
20 F9120 Rear Bearing 1
21 F1240 Front Bearing 1
22 F9122 Front Bearing Oil Seal 1
23 F9323 Drive Washer 1
24 F9324 Drive Washer Retainer 1
25 F1266 Propeller Washer 1
26 F1267 Propeller Nut Set 2
27 F1421 Piston 1
28 F1224 Piston Ring 1
29 F1222 Wrist Pin 1
30 F1323 Wrist Pin Retainer 2
31 F9131 Rocker Arm Set 2
32 F1213 Tappet Adjusting Screw Set 2
33 F1214 Tappet Lock Nut 2
34 F9134 Rocker Arm Shaft 1
35 F9135 Rocker Arm Screw 1
36 F1217 E Ring Set 2
37 F1235 Cam Gear 1
38 F9138 Cam Gear Cover 1
39 F1233 Cam Gear Cover O Ring 1
40 F9140 Cam Gear Cover Screws 2
41 F1242 Cam Gear Bearng 2
42 F1236 Cam Follower 2
43 F9143 Push Rod 2
44 F9144 Push Rod Covers 2
45 F1239 Push Rod Covers O rings 4
46 F9146 Con Rod 1
F9147A Rear Cover Assy.
47 F9147 Rear Cover 1
48 F9148 Disc Valve 1
49 F9149 Disc Valve Pin Retainer 1
50 F1229 Disc Valve Set 1
51 F9151 Disc Valve Pin E Ring 1
52 F9152 Rear Cover Gasket 1
53 F9153 Rear Cover Screws 4
F9354A Carburetor Assy.
54 F9354 Carburetor Body 1
55 F9355 Throttle Barrel 1
56 F9156 Low Needle Valve 1
57 F9157 Low Needle Valve O Ring 1
58 F9358 Throttle Barrel Seal 1
59 R6124 Throttle Barrel Retainer 1
60 F1260S Throttle arm 1
61 F1258 Throttle Stop Screw 1
62 F1259 Throttle Stop Spring 1
F1554S Needle Valve Set
63 F1554 Needle Valve 1
64 F1546 Needle Valve O Ring 1
65 F1555 Needle Seat 1
66 F1256 Needle Seat O Ring 2
67 F1557 Needle Valve Detent 1
68 F9164 Carburetor Gasket 1
69 F9165 Carburetor Screws 2
F9166A Regulator
70 F9166 Regulator Body 1
71 F1245 Regulator Adjusting Screw 1
72 F1246 Regulator O Ring 1
73 F9169 Diaphragm 1
74 F1248 Plunger 1
75 F1249 Regulator Spring 1
76 F1251 Regulator Screws 2
'99NOV.
26
25
23
36
31
32
40
38
24
34
80
21
39
79
78
33
77
22
41
45
43
44
45
42
37
35
41
14
4
28
30
73
74
70
76
74
75
72
71
12
13
27
7
6
5
46
17
15
16
18
2
11
60
55
69
61
58
3
62
77
30
29
50
56
57
69
53
66
65
67
64
63
53
51
54
68
59
47
52
48
8
49
19
NO.PART# DESCRIPTION QTY
77 F9174 Fuel Nipples 4
F9377A Muffler Set
20
1
77
78 F9377 Muffler 1
79 F9378 Exhaust Pipe 1
80 F9379 Lock Nuts 2
F9390 Gasket Set 4
F9391 O Ring Set 11
YAMADA MFG.CO.,LTD
67 Tsuchitori Inuyama Aichi 484-0917 JAPAN