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CORS-AIR M 25 Y / Black Devil 

 

INTRODUCTION 

 

Thank you for choosing our engine the CORS-AIR M 25 Y/Black Devil. 
Your engine has many superior features that have been developed, tested and introduced by JPX 

Italia over the few years this engine has been used in the ultralight industry.  The high quality Cors-Air 
M25Y/Black Devil is the most copied engine of its kind in the World.  Fly with confidence, you own the 
superior original.  

 

We invite you to spend some time reading this manual, which will let you discover all the features 

of your engine.  Advice on maintenance and operation will help you to have a reliable engine and to 
preserve your investment providing you years of reliable use.  Furthermore, we invite you to deliver this 
manual together with the engine should you decide to sell it, so it can be useful for the next owner as well.  
The manufacturer and the resellers are ready to answer your questions and if necessary to solve every 
problem because THE SAFTEY OF YOURSELF AND OTHERS IS THE MOST IMPORTANT THING 
FOR US. 
Welcome to the Cors-Air World! 
 
 

IDENTIFICATION OF THE OWNER 
 

Owner 

Address 

Engine serial number 

Reseller 

Address 

Owner’s signature 

Reseller’s signature and stamp 

Date of sale 

Summary of Contents for M25

Page 1: ...ou discover all the features of your engine Advice on maintenance and operation will help you to have a reliable engine and to preserve your investment providing you years of reliable use Furthermore we invite you to deliver this manual together with the engine should you decide to sell it so it can be useful for the next owner as well The manufacturer and the resellers are ready to answer your qu...

Page 2: ...g Sequence 9 Black Devil Engine Troubleshooting 10 THE ENGINE DOES NOT START 10 Flooded Engine 11 Decompressor Stuck Dirty Automatic Decompressors 11 THE ENGINE DOES NOT HOLD IDLE SPEED OR HAS AN IRREGULAR SPEED 12 THE ENGINE CANNOT REACH MAXIMUM SPEED 12 ENGINE RUNS LEAN REGARDLESS OF CARBURETOR ADJUSTMENT by Alex Varv 12 Additional Fuel System Troubleshooting 12 Pop off pressure testing 14 Decre...

Page 3: ...and Start engines only 17 STORAGE OF THE ENGINE 17 CORS AIR M 25 Y PARTS 18 CORS AIR M 25 Y ELECTRIC STARTER PARTS 19 ELECTRICAL SCHEMATIC Electric Start only 19 CORS AIR M 25 Y Black Devil Specifications 20 TECHNICAL FEATURES 20 Main Torques 20 EGT Placement 20 WARRANTY 21 DURATION OF WARRANTY 21 WARRANTY IS VOID IN THE FOLLOWING SITUATIONS 21 ...

Page 4: ...Never run the engine without the air filter Dirt and dust can enter the engine via the unprotected air intake resulting in poor engine performance and engine damage Do NOT keep engine at peak rpm after the take off except when absolutely necessary and for emergencies obstacles or sudden wind We advise installing small security cables from the frame to the following components to further secure the...

Page 5: ...ric wires Leaks from fuel hoses and fuel tanks Carburetor and engine s crankcase Propeller is not damaged or loose Exhaust pipe for cracks Muffler mounts and condition Frame is not bent or broken Rubber mounts are not cracked Reduction belt is not loose Safety wire is securely holding components All bolts fasteners are tight Safety netting Harness and bindings ASSEMBLY The CORS AIR M 25 Y engine c...

Page 6: ...er to verify if all components are functioning correctly but a further engine running in will be required A proper running in will prolong engine life Due to the high quality of the internal parts used on the Black Devil the engine is considered properly run in around 20 hours of operation Note Be sure to tune your engine properly before running in See Tuning Your Carburetor section below The reco...

Page 7: ... will add more fuel to the air richen the mix Turning the LO HI screws clockwise will lessen the fuel to air lean the mix Tuning your LO setting and adjusting the idle speed 1 Start your engine See STARTING YOUR ENGINE GENERAL TIPS and allow it to warm up for approximately 5 minutes If you have installed a CHT the cylinder head temperature will be near 200 F 93 33 C 2 Adjust the idle speed to the ...

Page 8: ... do this you must first determine the max RPM your engine is capable of It is important to note that finding the maximum rpm will briefly run the engine to the lean side Caution should be used to not run your engine lean for more than a few seconds otherwise engine damage can occur After securing the paramotor open the throttle to full power and maintain 1 Turn the HI screw to the left or right un...

Page 9: ...a blow tube to prime your carburetor press in and hold the relief valve on the side of the carburetor air silencer side and blow into the gas tank vent hose until you see the gas reach the carburetor through the clear fuel supply hose Once gas reaches the inlet for the carburetor continue blowing for 1 second to prime the engine Wait 15 seconds then secure the paramotor in preparation to start Usi...

Page 10: ...rimed properly Battery is fully charged if applicable Good spark plug connection Idle speed set too low 2400 RPMs recommended Belt is tight Auto Decompressor clean and closed Carburetor is clean adjusted properly Carburetor pop off pressure is incorrectly set Additional information concerning these systems is discussed below or is found or throughout this manual under the appropriate topic Not all...

Page 11: ...ecompressor is stuck partially open Symptoms a You will notice that in time you need more and more pulls to start the engine b Often before the engine starts you may hear popping noises in the exhaust Remedy 1 Remove the hose clamp on the vacuum line attached to the nipple of the decompressor 2 Remove the decompressor using a 15mm thin walled long socket that will fit on the body of the decompress...

Page 12: ...ove and disassemble the carburetor See the Walbro Carburetor Manual NOTE The round screen is on the fuel pump side 1 In order to clean the carburetor you should remove all the membranes HI and LO screws needle valve etc 2 Use a high quality carburetor cleaner with the supplied straw attached to the can Spray in the opposite direction of the fuel flow pushing the contaminants out the fuel inlet por...

Page 13: ...carburetor needs a well set pop off pressure The pop off pressure is the pressure at which the needle valve will open thus letting the fuel to enter the metering chamber HI and LO screws do control the mixture of fuel and air but if the pop off pressure is also a key factor Set too high it can lead to fuel starvation especially at high RPM Such a situation will cause engine overheating and possibl...

Page 14: ...s that the needle valve opened The value at which it opened is the pop off pressure Note The needle valve when opening will bleed off pressure till the valve closes again and the pressure stabilizes Decreasing the pop off pressure If the pop off pressure is too high we need to weaken the spring used to regulate the pressure As Walbro repair kits do not contain a spring we can achieve the same affe...

Page 15: ...d mark its length on a ruler or use calipers to determine its current length 2 Gently expand the spring by grasping at both ends and pulling the spring longer Use caution as it is better to err on the short side then to make the spring too long Expanding and then cutting the spring a few times will weaken it and you will end up with an erratically working carburetor If possible different springs g...

Page 16: ...ease of starting getting the most power from your engine and good engine operation All belt driven engines that use the poly V belt need a belt readjustment after a few hours If the belt slips the engine will be very hard to start as the additional torque the propeller causes is used to increase the compression of fuel After 2 3 adjustments the belt settles and will be maintenance free for many ma...

Page 17: ...small a gap a you run a risk that small magnetic particles can get between the armature of the ignition coil and the flywheel magnets This may cause a NO SPARK situation and an engine out STORAGE OF THE ENGINE To properly store winterize you Cors Air engine 1 Empty the fuel tank including the fuel lines and the carburetor 2 Disassemble the battery version with electric start 3 Unscrew the spark pl...

Page 18: ...INT DECOMPRESSOR with VALVE 14 DECOMPRESSOR 15 SEAL RING OF DRIVE SHAFT n pcs 2 16 COVER OF BACK SUPPORT BASE 17 BACK SUPPORT BASE 18 STARTER 19 COUPLER FOR STARTER 20 HANDWHEEL 21 COIL 22 REED VALVE 23 FLANGE FOR CARBURETTOR BED 24 CARBUTETTOR 25 FLANGE AIR FILTER 26 ADJUSTER FOR ACCELERATOR WIRE 27 PINION 50 or 52 2 mm 28 PULLEY 115 or 130 mm 29 BEARING OF REDUCTION PULLEY n pcs 2 30 CAM OF THE ...

Page 19: ... 31 DRIVE SHAFT complete with CONNECTING ROD 32 ELECTRIC STARTER 33 FLANGE FOR ELECTRIC STARTER 34 COVER OF BACK SUPPORT BASE 35 IGNITION 36 CHARGE REGULATOR 37 COIL 38 CROWN WHEEL complete with PINION ELECTRICAL SCHEMATIC Electric Start only ...

Page 20: ...R AVGAS 100LL and oil at 2 Oil synthetic top quality oil for 2 strokes engines Expenditure from 2 5 to 4 5 liter hour depending from the load and the speed Fixing to the frame 5 rubber anti vibration mounts Rotation counterclockwise in front of the propeller MAIN TORQUES Kg M NM DECOMPRESSOR only hand start version 2 0 20 NUTS TO FIX THE HEAD 2 2 22 NUTS TO FIX HALF CRANKCASE 2 5 25 BOLTS TO FIX T...

Page 21: ...ence of dirt sand or foreign bodies in the carburetor of the engine Corrosion through bad storage of the engine or inadequate preparation for storage of the engine Running the engine without an air filter fitted to the carburetor Miss assembly of engine parts or components not assembled by JPX Italia but by the manufacturer of the paramotor or by the end user supplied disassembled for packing and ...

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