Related Manuals for Hirth 2704
Summary of Contents for Hirth 2704
- Page 1 Göbler-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 Engine Type 2704 Manual Read the operating instructions completely before the assembly 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.
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Page 3: Table Of Contents
Table of Contents Chapter Topic Page Description of the engine, its systems, and essential technical information Overview of the engine 1.1.1 Model 2704 1.1.2 Description of the carburetion system 1.1.3 Description of the ignition system 1.1.4 Description of the cooling system Installation 1.2.1... - Page 4 Maintenance General 3.1.1 Scope 3.1.2 Common and special tools and initial torque values 3-1 Service intervals 3.2.1 Daily inspections 3.2.2 Periodic inspections Replacement parts Maintenance procedures 3.4.1 Carburetor 3.4.1.1 Synchronization of carburetors 3.4.1.2 Setting the fuel mixture adjustment screws 3.4.1.3 Cleaning the carburetors 3.4.2.
- Page 5 3.7.4 Engine does not develop full power 3.7.5 Excessive cylinder head temperature Ignition system wiring diagrams Single ignition wiring diagram Dual ignition wiring diagram...
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Page 6: Description Of The Engine, Its Systems, And
Description of the Engine, Its Systems, and Essential Technical Data 1.1 Overview 1.1.1 Model 2704 The Hirth 2704 engine (Illus. 1.1.1-1) from Göbler-Hirth Engines Ltd., is a fan-cooled, side- regulated, two-cylinder inline, two-stroke engine. The cylinders consist of an aluminium alloy coated with an abrasion-resistant surface. The cylinders are attached to the crankcase with bolts, washers and hexagonal nuts. -
Page 7: Description Of The Carburetion System
1.1.2 Description of the Carburetion System The fuel mixture system (Illus. 1.1.2-1) of the 2704 engine consists of one or two carburettors. Each carburettor is connected to the entry port of the cylinder by an aluminium intake socket and a rubber flange. The aluminium intake socket is screwed on to the cylinder with cylinder bolts and lock washers and the carburettor is secured in the rubber flange by a hose clamp. -
Page 8: Description Of The Cooling System
Illustration 1.1.3-3 (View of the ignition side with installed ignition system) 1.1.4 Description of the Cooling System The 2704 engine has a mechanically operated forced air-cooling, which is transposed on the exhaust side and fixed on the ignition side. (Illus. 1.1.4-1). -
Page 9: Installation
Illustration 1.1.4-1 (View of the Fan Housing and the Shroud) 1.2 Installation Instructions 1.2.1 Mounting and Securing the Engine The four threaded sockets (UNC- ½“) for mounting the 2704 engine (Illus. 1.2.1-1) are located on the underside of the crankcase. Illus. 1.2.1-1 (Engine Mounting Sockets) The engine should be mounted so that the moment transmitted from the engine to the mount can be on the broadest base as possible. -
Page 10: Airflow To The Engine
1.2.2 Airflow to the Engine The engine has to be installed in such a way that the fresh air stream supplied is sufficient to insure its cooling and adequate for the supply of air to the carburettor. For a cowled installation it is necessary to take care that the outgoing hot cool air stream is not allowed into the carburettors, since that will lead to a drastic reduction in performance. -
Page 11: Adjusting The Carburetors
The table below lists items that can be ordered from Göbler-Hirth Engines Ltd. -
Page 12: Cylinder Head Temperatures
Defective or improperly working thermal elements, temperature gauges, and measuring cables have to be replaced immediately. The maximum acceptable cylinder head temperatures mentioned by Göbler-Hirth Engines are based upon the proper positioning and calibration of the measuring devices within the range of these temperatures. -
Page 13: Technical Data
Illustration 1.4-1 (Identification Plate Position) 1.5 Technical Data Table 1.5-1 Manufacturer Göbler-Hirth Engines Ltd. Model 2704 Working process Two stroke Number of Cylinders 2, in line Displacement 625 cm Stroke 69 mm Bore 76 mm Compression Ratio 9.5 : 1... -
Page 14: Installation Sketch
1.6 Installation sketch 1/2"-13U N C... -
Page 15: Operating The Engine
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 engines are sealed from the time of their assembly in accordance with the maximum temperatures prescribed in Chapter 1 for cylinder heads and exhaust gas. -
Page 16: Starting Procedures
Starter (check connections, installation, and condition; correct if necessary) Carburetor (check connections, installation, and condition; correct if necessary) Ignition (check connections, installation, and condition; correct if necessary)) Fan (check installation and condition; check condition and tension of fan belt; correct if necessary) Cylinder heads (check installation and condition;... -
Page 17: Operating Conditions
2.4 Operating Conditions of the Engine During operation of the engine, it is necessary to monitor the cylinder head and exhaust gas temperatures of both cylinders. So long as the maximum-allowed cylinder head- or exhaust gas- temperatures are not exceeded, the engine can be operated at the selected power setting (including maximum power) without any time limitation. -
Page 18: Maintenance
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. numbers Special tools: Type GH-number Flywheel puller W 138... -
Page 19: Service Intervals
3.2 Service Intervals 3.2.1 Daily Inspections Before operating the engine, a thorough daily inspection should be carried out. Observe the following points: 1. Air filter - check condition and installation 2. Starter - check condition and installation 3. Ignition system - check condition, fastening, and connections 4. -
Page 20: Maintenance Procedures
3.4 Maintenance Procedures 3.4.1 Carburetor The carburetors of Hirth engines are jetted in such a way by the manufacturer that the engine is guaranteed to run thermally secure. Since interference with the jetting of the carburetors may lead to overheating, and thus to the destruction of the engine, such intereference must be avoided. -
Page 21: Cleaning The Carburetors
3.4.1.3 Cleaning the Carburetors Turn off fuel switch before cleaning carburetors. Open the spring clip which holds the float chamber against the carburetor. Move float chamber downward carefully since it is filled with fuel. Remove the fuel from float chamber along with any debris. Should debris be in float chamber, the fuel filter in the intake line between tank and fuel pump should be checked and, if necessary, replaced. -
Page 22: Spark Plug Installation And Removal
3.4.4.2 Spark Plug Installation and Removal To remove spark plugs, disconnect the spark plug cap. Loosen spark plug with spark plug wrench and unscrew. Before installing the new or still usable spark plug, the electrode gap (0.8 mm) has to be checked with a feeler gauge and adjusted as required. -
Page 23: Cylinder Head
Hirth service center Cause: -No spark or weak spark due to defective spark plug, spark plug cap, or a defective ignition Solution: -Replace spark plug, spark plug cap, or have the manufacturer or an authorized Hirth service center replace the defective ignition... -
Page 24: Engine Will Not Come Up To Idle Speed
Solution: -Turn the low speed adjuster so that correct idle is insured Cause: -Defective ignition Solution: -Ship engine to Göbler-Hirthmotoren or an authorized Hirth service center 3.5.3 Engine Runs Rough, Uneven, and with Insufficient Power Cause: -Dirty air filter Solution:... -
Page 25: Excessive Cylinder Head Temperature
Cause: -Incorrect adjustment of carburetors, butterfly valve not fully open Solution: -Adjust butterfly valve accordingly 3.5.5 Excessive Cylinder Head 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:... -
Page 26: Wiring Diagrams
The following two diagrams for the single- and dual-ignition systems show the PVL ignition system. Attention: Read also the Hirth-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. - Page 27 Schlüsselschalter key switch Verbraucher 30 A 032.22 instruments Startrelais Start 032.20 blau * blue * 6,3 mm E-Starter 028.10 029.7 12 V + gelb Regler yellow Gleichricht. Generator E-Box gelb rectifier regulator yellow 4,8 mm 6,3 mm Zünd- spule ignition Drehzahlmesser coil tachometer...
- Page 28 Schlüsselschalter key switch Verbraucher 30 A Start 032.22 instruments Startrelais blau * 032.20 blue blau E-Starter 6,3 mm 028.10 blue Taster tip switch E-Box 1 12 V + 029.7 gelb Regler yellow Generator Gleichricht. gelb rectifier regulator yellow 4,8 mm 6,3 mm 4,8 mm 6,3 mm...