2009 KTM 50 SX, 50 SX Junior & 50 SX Mini Repair Manual (P/N 3206060en)

KTM's 2009 repair manual, Article no. 3206060en, covers the 50 SX, 50 SX Junior, and 50 SX Mini, with engine repair, chassis service, and electrical diagnosis for these three variants.

Text search, bookmarks, and diagram detail: The service text is searchable, with embedded bookmarks for procedures, specifications, and the index. The HOME bookmark requires a separate menu PDF. Small wire-color labels in the ignition diagram are readable when enlarged.

• Engine repair: Engine removal and installation, crankcase disassembly, connecting-rod bearing replacement, cylinder and piston inspection, and reassembly of the crankshaft, transmission shafts, and kickstarter.

• Carburetor and lubrication: Model-specific Dell'Orto carburetor service, throttle and choke checks, idle adjustment, and separate oil-pump service for the 50 SX Mini.

• Centrifugal force clutch: Clutch-shoe inspection, removal and installation, engagement-speed testing, and adjustment procedures using the specified washers.

• Suspension and steering: Marzocchi fork servicing, WP shock absorber rebuilds, nitrogen filling, and steering head bearing greasing and adjustment.

• Cooling and brakes: Water-pump overhaul, coolant filling and bleeding, front and rear brake fluid replacement, brake pad changes, and wear checks.

• Ignition and diagnosis: Selettra ignition testing, stator-to-rotor clearance adjustment, a wiring diagram with component legend, and symptom-based troubleshooting charts.

KTM assumes repair work will be performed by a fully trained mechanic with the specified special tools and workshop equipment.

Engine Repair, Piston Sizing, and Clutch Setup

Cylinder classes A/B and piston sizes 1/2 are listed alongside mounting-clearance and wear-limit data. Together with piston ring end-gap checks, these references support component matching and assessment during a top-end repair.

X-distance checking and setting use adjustment gauge 45129006000. The manual explains how an incorrect piston protrusion setting can cause power loss, knocking, or overheating.

Clutch procedures distinguish the required spacing washer from engagement-adjustment washers and specify consistent washer arrangements across all three shoes. Engagement-speed testing uses tachometer 45129075000.

Dell'Orto Carburetors and Mini Oil Pump

The carburetor sections distinguish the PHBG 19BS (50 SX), PHVA 14DS (50 SX Junior), and PHVA 12XS (50 SX Mini). Separate assembly and idle-setting instructions help you select the procedure and jetting data for the fitted carburetor.

The SX and Junior use premix lubrication; the Mini has separate oil injection. Mini-specific coverage includes oil-pump removal, installation, drive-gear work, and bleeding.

Reed valve housing, diaphragm, and intake-flange inspection are covered alongside air filter cleaning and main silencer repacking.

Marzocchi Forks and WP Shock Absorbers

Suspension chapters cover fork seals, oil filling, and air-chamber adjustment, plus WP 3614 BAEM damper inspection and piston-rod assembly. Separate SX and Junior/Mini procedures address damper and spring assembly.

It supplies factory reference values for static and riding sag, aiding in chassis setup tailored to different rider weights. Fork oil volumes and shock absorber gas pressures are tabulated with the suspension data.

The shock absorber instructions identify the different heim-joint collar bushings and warn that incorrect placement makes the shock rub against the swingarm.

Cooling, Brakes, and Chassis Maintenance

Water-pump repair covers the impeller, shaft, bearing, and seal; coolant sections address refilling and air removal. Brake chapters specify approved fluids, pad wear limits for both calipers, and lever adjustment.

Chassis torque tables include triple clamp bolts, wheel spindles, and engine carrying screws. The reference sections also list gear oil capacities and approved-fluid specifications. Wheel removal, spoke tension, chain adjustment, and scheduled maintenance have their own procedures.

Follow the manual's precautions for brake service and the pressurized, nitrogen-filled shock absorber.

Selettra Ignition Tests and Fault Charts

The Selettra 2p D36 section provides resistance and peak-voltage checks for the ignition components, including use of peak voltage adapter 58429042000. The wiring diagram identifies the kill switch, alternator, ignition coil, and wire colors.

Troubleshooting tables connect starting, idling, power-loss, and overheating symptoms with possible causes and relevant checks. Separate entries cover oil from the vent hose and water in the gear oil.

English PDF and Included Pages

A single, printable English 159-page PDF contains numbered pages 1–156 (including blank page 139), plus the front cover, one unnumbered blank page, and the back cover.