Hirth 2704, Service Manual

Page 1: ... Hirthmotoren KG Service manual Engine 2704 Göbler Hirthmotoren KG Max Eyth Str 10 D 71726 Benningen Germany Tel 0049 7144 8551 0 Fax 0049 7144 5415 e mail info hirth engines de internet www hirth engines de ...

Page 2: ...ly of the engine or before starting the engine In the interest of the ongoing developments of our products we reserve the right to change the delivery volume in form technique and supply We also ask for your understanding that the data in this instruction manual gives no further claims ...

Page 3: ...gine 1 4 1 2 2 Airflow to the engine 1 5 1 2 3 Fuel system layout 1 5 1 2 4 Adjusting the carburetors 1 6 1 2 5 Securing spark plug caps Inverted installation 1 6 1 2 6 Disconnecting ignition system 1 6 1 3 Engine instruments 1 7 1 3 1 Cylinder head temperatures 1 7 1 3 2 Exhaust gas temperature 1 7 1 3 3 Fuel pressure 1 8 1 4 Identification plate 1 8 1 5 Technical data 1 9 1 6 Installation sketch...

Page 4: ...l and pulse lines 3 4 3 4 3 1 Inspection of fuel line 3 4 3 4 3 2 Inspection of pulse line 3 4 3 4 4 Spark plugs and spark plug caps 3 4 3 4 4 1 Checking spark plug caps 3 4 3 4 4 2 Spark plug installation and removal 3 5 3 4 4 3 Condition of spark plugs 3 5 3 4 5 Fan 3 5 3 4 5 1 Removal and installation of cooling system 3 5 3 4 5 2 Removal and installation of fan housing 3 5 3 4 5 3 Changing the...

Page 5: ... 7 4 Engine does not develop full power 3 7 3 7 5 Excessive cylinder head temperature 3 8 4 Ignition system wiring diagrams 4 1 4 1 Single ignition wiring diagram 4 2 4 2 Dual ignition wiring diagram 4 3 ...

Page 6: ... bearing The crankshaft is made of Chromoly steel 42CrMo4 and is positioned in five grooved ball bearings It is a constructed crankshaft in which the individual parts are pressed together to form the complete crankshaft Two grooved ball bearings are attached on the power take off side two more between the crank control handle and one on the ignition side The power take off is cone shaped and has a...

Page 7: ...dry air filters Illustration 1 1 2 1 Fuel Mixture or Carburetion System 1 1 3 Description of the Ignition System The ignition system Illus 1 1 3 1 1 1 3 2 consists of an armature plate a magneto an E Box two ignition coils and the ignition cables with spark plug caps The ignition is entirely electronic and has an e prom for a free programmable electro dynamo magnetic ignition There is generator po...

Page 8: ...ed on the exhaust side and fixed on the ignition side Illus 1 1 4 1 The fan is mounted inside the fan housing by a cam It is propelled by a flat belt and a catch which is attached to the magneto wheel of the ignition The cool airflow built up by the fan is divided over the two cylinders for maximum cooling through the fan shroud surrounding the two cylinders The hot cool airflow is blown off into ...

Page 9: ...as possible because the engine vibration can result in a mounting that is not secure This leads to problems with the fuel mixture i e foaming of the fuel uncontrolled flapping of the fuel pump membrane and with that to unsafe operation of the engine Recommendation The engine is bolted to a plate that is about twice the size as the underside of the engine the wider the better On the two outsides of...

Page 10: ...always be installed between the diaphragm pump and fuel tank The diaphragm pump should be installed at a place with the least influence of vibration or heat Take care to insure that with an upright installation of the diaphragm pump the fuel exit is on top The placement of the connecting pieces can be recognized by arrows on the casing The central connection of the fuel pump is the impulse connect...

Page 11: ...s must be brought on the same level in the idle position using the idle stop screws measure and adjust the opening height of both slides to the same level When pulling the slides open they should both be synchronized to lift off from the adjustment screws at the same time to open the passage 1 2 5 Securing the Spark Plug Caps Inverted Installation If the engine is installed in an inverted position...

Page 12: ...measuring devices within the range of these temperatures 1 3 2 Exhaust Gas Temperature The exhaust gas temperature see Table 1 5 1 is measured individually for each cylinder at the exhaust bend manifold An exhaust bend that is prepared for installation of thermal elements may be ordered from Göbler Hirth Engines A staff shaped thermal element will be pressed into a special sealing screw joint Of g...

Page 13: ...ion System Electronic dynamo magneto ignition single or dual Generator 250 W 12 V Spark Plugs single ignition 023 29 BR8HS NGK W24FSRU ND Spark Plugs dual ignition 023 28 BR8ES NGK W24ERS ND Ignition timing 16 BTDC at 2000 RPM Fuel mixing system 1 BING 54 38 134 1 air filter dry 2 BING 54 38 135 2 air filters dry Cooling Air cooled by axial blower turned by a flat belt Mixture 1 50 Fuel Premium le...

Page 14: ...1 6 Installation sketch 36 377 223 1 2 13UNC 24 450 112 36 56 31 96 210 208 383 ...

Page 15: ...AN IMPEDE THE EXIT OF HOT AIR BE SURE THAT HEATED AIR IS NOT SUCKED INTO THE CARBURETORS USE ONLY RESISTOR TYPE SPARK PLUGS AND RESISTOR PLUG CAPS EVERY TIME A WARM UP PHASE BEFORE RUNNING THE ENGINE UNDER LOAD 2 2 Break In Procedures Hirth engines have no explicit break in procedures since the Nikasil coating of the cylinders and the Aluminium pistons do not have to adjust to each other The engin...

Page 16: ... 2 Use choke if engine is cold but not if engine is warm or hot 3 Set throttle at idle carburettor slide should also be at idle position 4 Close ignition circuit Turn ignition switch to ON Position 5 Start engine use starter for maximum of 10 seconds 6 If the cold engine will take the gas the choke can be retarded check by advancing throttle lightly 7 Allow engine to warm up for 3 minutes at 1 4 p...

Page 17: ...g maximum power without any time limitation Furthermore it is recommended that fuel pressure be monitored during engine operation Insufficient fuel pressure can lead to loss of performance and cause the engine to miss 2 5 Engine Shutdown Before turning the engine off it should be run at idle power for one minute Because of the fan operation the cylinder head temperature should go down This procedu...

Page 18: ...hops Tools metric tools Type Size Type Size Open end wrench 7 Open end wrench 8 Open end wrench 10 Open end wrench 13 Hexagonal socket wrench 3 Hexagonal socket wrench 4 Hexagonal socket wrench 5 Hexagonal socket wrench 6 Sparkplug wrench no size given Sparkplug wrench 20 6 20 8 Torque wrench 0 100 Nm Special tools can be procured commercially from Göbler Hirth Engines Ltd under specific G H numbe...

Page 19: ...nd the connections 3 2 2 Periodic Inspections Inspection interval 25 h 50 h 100 h 500 h Cooling Airway check for free flow and freedom from pollutants X X X Baffles check for damage and cracks X X X Carburetor Air filter clean X X X Carburetor adjustments check X X X Carburetor clean X X X Fuel system Fuel filter clean X X X Fuel lines and connections check X X X Impulse line to the membrane pump ...

Page 20: ...f the carburetor intake 3 4 1 1 Synchronization of Carburetors In order to insure even performance and a smooth running engine both carburetors have to be synchronized precisely Note that the idle adjustment screw holds the slide in the same position on both carburetors Measure and adjust the opening height on both carburetors for this The two cables which move the slide in the carburetor usually ...

Page 21: ...pull the filter free from the carburetor flange To install the air filter put it on the carburetor flange and fasten it back with the clamp 3 4 2 2 Cleaning the Air filters Wash the air filter in gasoline and then dry by using compressed air to blow out from the inside to the outside Check filter for damage and if necessary replace it 3 4 3 Fuel and Pulse Lines 3 4 3 1 Inspection of Fuel Lines Che...

Page 22: ...ark plug caps Remove entire muffler after the elbow in the exhaust manifold see later chapter Remove both screws to the crankshaft housing underneath the elbow of the exhaust manifold Then remove the screws to the fan housing on the side of the cool air exit Pull off the shroud over the elbow of the exhaust manifold To install the shroud reverse the process used for removal Should there be any dam...

Page 23: ...ads and cylinders for places on which exhaust gas has blown through These places can be recognized by black lines over the seal and burned residue on the cooling fins Should there be such places the cylinder head must be immediately replaced Check the indentation on the cylinder head for the black residue If present remove it and eventually change the type of oil used 3 5 Trouble Shooting 3 5 1 En...

Page 24: ...or replace fuel filter Cause Fuel mixture has too much oil in the gasoline Solution Empty tank and fill with fuel of the proper mix Cause Defective spark plug caps Solution Replace the spark plug caps 3 5 4 Engine Does Not Develop Full Power Cause Dirty air filter Solution Clean or replace filter Cause Dirty fuel filter Solution Clean or replace the fuel filter Cause Fuel mixture has too much oil ...

Page 25: ... Temperature Cause Fan belt too loose or defective Solution Tighten fan belt or replace Cause Defective fan Solution Replace the fan Cause Defective shroud Solution Replace shroud Cause Insufficient cool air reaching the blower Solution Install blower so that fresh air gets to the blower unhindered Cause Dirty carburetor Solution Clean carburetor ...

Page 26: ...th information 0065 Additional information on voltage supply and ignition system These wiring diagrams should be understood as suggestions for the periphery of the ignition system Cross section in general 1 5 mm2 Cross section from to E Starter 16 mm2 4 1 Single ignititon wiring diagram see next page 4 2 Dual ignition wiring diagram see overnext page ...

Page 27: ...Anzahl Änderun Tag Name 2702 03 04 05 06 3202 03 3502 03 Mindestabstand zu anderen Stromführenden Leitungen 100 mm Rohteil Nr Maßstab Zeichnungs Nr Minimum distance to other current wires 100 mm 4 in 14 AA 104 regulator Fuse E Box battery 12V Gehäuse Batterie 12V case 12 V Regler Gleichricht rectifier gelb gelb yellow yellow 029 7 Drehzahlmesser tachometer 029 14 alt grün n green Generator Sicheru...

Page 28: ...04 05 06 3202 03 3502 03 Mindestabstand zu anderen Strom führenden Leitungen 100 Rohteil Maßstab Zeichnungs Nr Minimum distance to other current wires 100 mm 4 in 14 AA 105 E Box 1 E Box 2 battery 12V Gehäuse Batterie 12V case 12 V 029 7 Regler Gleichricht rectifier regulator gelb gelb yellow yellow Taster tip switch a Drehzahlmesser tachometer 029 14 alt green n grün Generator Sicherung Fuse Sich...