1985–1995 Kohler Magnum M18 / M20 Twin-Cylinder Engine Service Manual (P/N TP-2204-B)

This Kohler service manual covers 1985–1995 Magnum M18 and M20 twin-cylinder engines, including electric-start, generator, and pump applications. Publication TP-2204-B, revised May 1993, covers routine maintenance, fault diagnosis, internal engine repair, and reassembly.

Text search, bookmarks, and diagrams: PDF text search is not available. Embedded bookmarks open the main sections, including the separate Kohler and Walbro carburetor chapters. Wiring labels are legible; zoom helps with smaller terminal markings.

• Engine repair: Complete disassembly and reassembly, cylinder-barrel reconditioning, valve service, piston and ring inspection, and crankshaft and connecting-rod checks.

• Fuel systems: Kohler adjustable-jet and Walbro fixed- or adjustable-main-jet carburetor repair, float adjustment, throttle and choke shaft service, and LPG coverage.

• Governor controls: Centrifugal flyweight governor adjustment, sensitivity settings, early and later throttle-stop designs, and M20 linkage and dampening-spring service.

• Lubrication: Gerotor oil-pump service, pressure-relief valve inspection, Oil Sentry pressure-switch testing, and engine-mounted or remote oil-filter arrangements.

• Electrical systems: Electronic magneto ignition diagnosis, regulated charging-system tests, and Bendix drive and solenoid shift starter service.

• Maintenance and diagnosis: Crankcase vacuum, compression, and cylinder leakdown tests, cold valve-to-tappet clearance checks, cooling-fin maintenance, and square, dome, or anti-icing air-cleaner service.

• Service specifications: Component-specific torque tables, piston-to-bore clearances, crankshaft running limits, fluid-capacity information, valve settings, and electrical test values.

Suited to experienced small-engine mechanics equipped for precision measurement; the valve-seat and cylinder-reconditioning procedures also require appropriate machining equipment.

Engine Diagnosis and Reconditioning

The cylinder leakdown results table distinguishes ring or cylinder-wall leakage from intake- and exhaust-valve faults, helping narrow the cause of low compression before teardown. Tool references include cylinder leakdown tester 47 800 02 and water manometer 25 800 50.

Reconditioning extends to cylinder honing, valve-guide and seat replacement, Style D piston identification, and Posi-Lock connecting rods. New and reused rods have separate tightening requirements. Cylinder-head tightening-sequence charts support reassembly.

Camshaft and valve changes: Separate service notes cover updated camshafts and matching tappets, the 30-degree exhaust-valve conversion, and model-specific valve kits. They also address side-specific replacement cylinder barrels and differences between Magnum connecting rods and earlier KT17/KT19 designs.

Carburetors, Governors, and LPG Equipment

Carburetor exploded views and float-level illustrations accompany the cleaning, inspection, repair, and adjustment procedures. Kohler throttle/choke shaft replacement and Walbro welch-plug service are covered. Attempting to remove the Walbro's nonserviceable fuel-inlet seat can damage the carburetor.

Optional thermo-electric automatic choke and fuel shutdown controls have their own checks. The M20 linkage update identifies kit 52 755 64, while governor instructions distinguish early stop tabs from later stop brackets.

LPG scope: Dual-fuel coverage addresses adapter venturi identification and differences between Century regulators and Beam 50/50E secondary regulators. A separate section covers Kohler LPG carburetors. Equipment-supplied tanks and other LPG components require the equipment manufacturer's instructions; the LPG carburetor throttle-shaft assembly is nonserviceable.

Oil-Pump Access and Closure-Plate Variants

The pump cover, rotors, and pressure-relief valve are accessible through the rear closure plate. Pump-shaft, drive-gear, and oil-pickup service requires crankcase separation. Oil Sentry coverage distinguishes engine-shutdown and warning-light applications.

Reassembly distinguishes closure plates designed for a fiber gasket from those designed for silicone sealant; their sealing arrangements are not interchangeable. Earlier splined-crankshaft applications have separate alignment-tool requirements, while later engines use permanent locating pins.

Ignition, Charging, and Starter Repair

The 15-amp and 25-amp wiring diagrams accompany tests that distinguish stator faults from rectifier-regulator faults. Ignition coverage includes module secondary-resistance testing, early kill-lead diodes, and magnet-to-module air-gap illustrations; ignition timing itself is not adjustable.

Starter drive component layouts support spline service, brush replacement, commutator inspection, and reassembly for the two starter types. Applying battery voltage to the magneto ignition circuit can burn out the module, a specific caution addressed in the electrical section.

Safety notice: Follow the manual's precautions for accidental starting, rotating parts, and flammable fuels. Consult a qualified technician if you are uncertain about a procedure.

English PDF and Included Pages

One printable English PDF contains 139 pages: 136 pages of safety, specifications, and service material, plus one front cover, one contents page, and one publication-details back cover. All three supporting pages are included in the total.