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(4) Inspection of the air filter

 

Check for the damages on the air filter: cracks, tears, wears, deformation, and deterioration. Replace the air 

filter set in case of any damage.

 

Remove visible foreign objects from the surface of the air filter with fingers.    Do not use compressed air 

otherwise the air filter will get damage.    Also, if you blow off the dust with compressed air from the outside 

filter, the dust in the filer will come into the engine through the carburetor.

 

This is a wet type air cleaner.    In case it gets dry or gets dust, wash and re-oil it as follows.

 

i) Loosen the hose clamp to remove the air cleaner unit.

 

ii) Wash the air filter using air filter cleaner available in the market.    Follow the instructions of air filter 

cleaners.

 

WARNING

 

Wash the air filter only outdoors or in well ventilated area away from any source of fire.

 

iii) After washing the air filter, dry and re-oil it with air filter oil available in the market.    Follow the instructions 

of air filter oil.

 

iv) Attach the air filter to the carburetor with the hose clamp with fastening torque of 1.0N

m.

 

 

(5) Inspection of the spark plug cap and the high-tension cord

 

Remove the plug cap.    Pull and shake the plug cap holding its body tight.    Do not pull the high-tension cord 

or use a screw driver to remove the plug cap from the spark plug.    It may ruin the plug cap.

 

Check for tear and worn on the surface of the high-tension cord.    In case the outer metal mesh is worn more 

than 1/2 of its thickness, replace the whole ignition system.    The high-tension cord cannot be replaced itself 

alone.    In case it is worn less than 1/2, use a spiral cord protector.    In case string of the outer metal mesh is 

cut considerably, more than 5 strings per 10mm cord length, replace the ignition system.    If less, reinforce the 

cord with a spiral cord protector.

 

Check if the caulking parts (Fig.2) come off.    Make 

sure to caulk the parts firmly.    Send back the ignition 

system for repair to us if it is requested.

 

Check if the ring is placed at the right position (Fig.2).   

If the ring is damaged or lost, replace CODE 

No.74002200 PLUG CAP SET.

 

 

Check for damage of the silicon part in the plug cap.   

In case of damage, replace CODE No.74002200 PLUG 

CAP SET.

 

Fit the plug cap on the spark plug after inspection.

 

 

(6) Inspection of the spark plug

 

Remove the spark plug using a 14mm spark plug socket removal tool available in the market.

 

Check for damages on the spark plug.    Replace it if any damage on it.

 

Clean the center and ground electrodes with a wire brush.

 

Check the spark gap of NGK CM-6 spark plug.    It should be 0.4 ~0.5

 

リング

/RING 

 

Summary of Contents for GT120THU

Page 1: ...2 stroke gasoline engine for UAV GT120THU Maintenance manual Ver 1 03 2020 OCT 26 O S ENGINES MFG CO LTD ...

Page 2: ...INSPECTION AFTER EVERY 50 HOURS OF OPERATING TIME 10 2 Inspection of the regulate rectifier 1 Adjustment of the tension of the generator belt 3 Inspection of the generator 4 Ignitor inspection 7 INSPECTION AFTER EVERY 100 HOUR OF OPERATING TIME 11 1 Disassembling the engine for inspection and replacement Inspection and maintenance of the cylinder blocks Inspection and maintenance of the pistons In...

Page 3: ...2 20 3 Replacing the fuel filter 4 Replacing the fuel tubes 5 8 EXPLODED VIEW 17 9 PARTS LIST 18 ...

Page 4: ...might cause it to ignite Do not smoke or allow anyone else to smoke near to it Carry out mixing of gasoline and oil outdoors or in a well ventilated place away from any source of fire Refill the fuel tank only after the engine is well cooled down or there is a danger of fire The engine generates considerable heat Do not touch any part of the engine until it has cooled down Never operate your engin...

Page 5: ...containing loose gravel or sand The propeller may throw such material in your face and eyes and cause injury If you have to carry the aircraft to runway with the engine running make the engine on idling Keep the propeller pointed away from you and others with keeping an eye on it Turn off the ignition module when you stop the engine or fully close the carburetor via the transmitter to shut off the...

Page 6: ...e air blow or there is a possibility for it to rotate beyond the limited and cause damages 18 In case you check rotation of a ball bearing by feeling with fingers hold the inner race and turn the outer race to check or vice versa 19 When you remove a ball bearing pressing the steel balls check and confirm smooth rotation with feeling of fingers Replace it with new one if you feel it rough 20 Apply...

Page 7: ...enance of the pistons iii inspection and maintenance of the piston rings iv inspection and maintenance of the piston pins v inspection and maintenance of the crankshaft and the connecting rods vi inspection and maintenance of the ball bearings vii inspection and maintenance of the carburetors viii inspection and maintenance of the generator ix inspection and maintenance of the starter motor x insp...

Page 8: ... if there are 3 Inspection of the fuel filter Filter Body A of the fuel filter is transparent to check for the dust in the filter Wash the filter following the processes below 2 7 Remove the tube cramps at the both ends of the filter Take out the fuel filter putting a piece of rug under the filter to catch and absorb the fuel that will run out of the tubes when they are disconnected Disassemble th...

Page 9: ...ug cap holding its body tight Do not pull the high tension cord or use a screw driver to remove the plug cap from the spark plug It may ruin the plug cap Check for tear and worn on the surface of the high tension cord In case the outer metal mesh is worn more than 1 2 of its thickness replace the whole ignition system The high tension cord cannot be replaced itself alone In case it is worn less th...

Page 10: ...le servo and the choke servo Turn on the operation system and move up and down the throttle stick and check if the throttle servo moves smoothly without strange noise Replace it if you recognize strange noise from the servo or unsmooth movement of it Turn on the radio control system check if the throttle servo horn and the choke servo horn are fixed tight Turn on the operation system and shake the...

Page 11: ... pointed with the arrow in Fig 4 Turn the generator to adjust the deflection within 0 5 1 0mm Fix the M5 screw after adjustment with fastening torque 5 4N m 2 Inspection of the regulate rectifier Start the engine and move the throttle up until the generator can generate the set voltage 3 000rpm when the set voltage is 12V 6 000rpm when the set voltage is 24V Measure the voltage of the output when ...

Page 12: ... be a new one but a used one ii Cut off a part of the spark plug body as shown in the picture Detach the both plug caps and remove the spark plugs Attach the special spark plug mentioned in to the plug cap Turn on the starter and check if there is a spark between the center electrode and the spark plug body which is cut short as shown in Fig 6 Replace the ignitor if there is no spark Note The spar...

Page 13: ...nspection and maintenance of the pistons i Remove the piston pin retainers circlips the piston pin wrist pin and the piston ring from the piston Do not use the used piston pin retainers when you assemble the piston again ii Wash the piston with gasoline or kerosene WARNING When you wash the part with gasoline or kerosene carry out the work only outdoors or in well ventilated area away from any sou...

Page 14: ...on buildup and remove the carbon buildup Do not file off the ring itself but only remove the carbon buildup iii Check the outer surface of the ring for heat mark or any scratches Replace the ring if there are damages on it Check the inner wall of the cylinder block for damage as well It is likely to have damages on it when the outer surface of the ring is damaged iv Check the bottom side of the pi...

Page 15: ...r ring to confirm that it turns smoothly Replace the ball bearing if it does not turn smoothly Ball bearings are important parts in the engine so replace immediately when you find something abnormal Inspection and maintenance of the carburetor Some parts cannot be assembled upside down left side right or inside out even they look the same Follow the instructions 16 19 in 3 Notification on inspecti...

Page 16: ...engine Check the generator including connectors lead wires for any damages If there are any damages replace the part ii Remove the driven pulley 3G16 and the generator adapter from the generator Measure the diameter shown in Fig 16 at 12mm from the shaft end with a blade micrometer In case the diameter is φ7 960 or less replace the shaft iii The generator shaft and the ball bearings of the generat...

Page 17: ...rosene carry out the work only outdoors or in well ventilated area away from any source of fire to prevent a fire Inspection and maintenance of the generator belt and pulley Remove the generator belt and check the following i worn notches ii missing notches iii cracking on the outer surface iv cracking between the notches v fabric exposed on the side of the belt vi oil adhering to the surface of t...

Page 18: ...17 20 7 EXPLODED VIEW ...

Page 19: ...ト一式 CRANKSHAFT ASSY 13 4AA07020 ドリブンプーリ 3G16 DRIVEN PULLEY 3G16 13 1 79820406 セットスクリュー M4X6 10 イリ SET SCREW M4X6 10 SET 締付トルク Fastening Torque 1 5N m 14 4AA07050 ベルト 3GT 255 10 BELT 3GT 255 10 15 4AA32000 ボール ベアリング ジェネレータ BALL BEARING GENERATOR 16 54059001 ジェネレータアダプタ GENERATOR ADAPTER 17 79871515 キャップスクリュー M5X15 10 イリ CAP SCREW M5X15 10 SET 締付トルク Fastening Torque 5 4N m 18 4AA07040 ジェ...

Page 20: ...2 79871140 キャップスクリュー M3X12 10 イリ CAP SCREW M3X12 10 SET 締付トルク Fastening Torque 1 1N m 43 4AA07290 サーボマウント L SERVO MOUNT L 44 4AA07280 サーボマウント S SERVO MOUNT S 45 4AA07300 サーボ BLA1HF SERVO BLA1HF 46 79871030 キャップスクリュー M2 6X10 10 イ リ CAP SCREW M2 6X12 10 SET 締付トルク Fastening Torque 0 18N m LOCTITE 222 使用 47 79872026 平ワッシャ 2 6 10 イリ WASHER 2 6 10 SET 48 4AA07060 リンケージボール LINKAGE BALL 49 79850020...

Page 21: ...締付トルク Torque 4 0N m 70 4AB81000 キャブレター HS 324A CARBURETOR HS 324A 71 4AB81410 スロットルアーム THROTTLE LEVER 72 4AA83000 エアクリーナーアダプタ AIR CLEANER ADAPTER 73 79871555 キャップスクリュー M5X55 10 イリ CAP SCREW M5X55 10 SET 締付トルク Torque 5 4N m 74 4AA84000 エアクリーナ PK 7E AIR CLEANER PK 7E 付属品 ACCESSORIES 78300000 ガソリン用燃料フィルター S GASOLINE FUEL FILTER S 70000001 ホースクリップ φ6 5 イリ HOSE CLIP 6 5PCS SET オプション OPTION 75 4AA...

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