Filter
Top Products
ENGLISH
43
Carburetor adjustment *
Basic information on the original carburetor setting
The original carburetor setting was adapted for an altitude of approx. 500 meters (1600 ft.) above sea level, and the ambient
temperature of approx. 20° C (68° F), mainly for off-road use and central European premium-grade fuel (95 ROZ).
Mixing ratio (2-stroke motor oil : super fuel) 1:60
Basic information on changing the carburetor setting
Always start with the original carburetor setting (the provided factory setting is meant for break-in operation; after the break-in period,
the carburetor needs to be adjusted according to the carburetor datasheet - see appendix). Essential requirements are a clean air fil-
ter system, air-tight exhaust system and an intact carburetor. Experience has shown that adjusting the main jet, the idling jet and the
jet needle is sufficient and that changes of other parts of the carburetor will not greatly affect engine performance.
RULE OF THUMB: high altitude or high temperatures > choose leaner carburetor adjustment
low altitude or low temperatures > choose richer carburetor adjustment
– Only use premium-grade gasoline ROZ 95 (USA = Premium PON 91) mixed with high-grade two-stroke engine oil. Other types of
gasoline can cause engine failure, and will void your warranty.
– Only use high-grade 2-stroke engine oil of known brands (e. g. Motorex Cross Power 2T).
– Not enough oil or low-grade oil can cause erosion of the piston. if you use too much oil the engine can start smoking and foul the
spark plug and the exhaust control system.
– In the case of a leaner adjustment of the carburetor, proceed cautiously. Always reduce the jet size in steps of one number to avoid
overheating and piston seizure.
NOTE: If the engine does not run properly despite a changed adjustment, look for mechanical faults and check the ignition system.
General information on carburetor wear
Engine vibrations subject the throttle slide, jet needle, float needle valve and the needle jet to extreme wear. Wear leads to malfunctio-
ning of the carburetor (e.g. over-enrichment). These parts should be replaced after 100 operating hours. The carburetor body, main jet
holder and the float support should be replaced after 200 operating hours.
Bleeding the hydraulic clutch *
The clutch control needs to be bled as soon as the resistance in the clutch
lever starts to feel unresponsive. You will need to use a bleeding syringe (spe-
cial tool). Please note that Motorex 75 clutch fluid must be used for the 125/200
models and Motorex DOT. 5.1 brake fluid for the 250/300 models.
Both are available from your KTM dealer.
Turn the handlebar until the master cylinder is in a horizontal position, remove
the screws [1], the cover [2] and the rubber boot [3].
MAINTENANCE WORK ON CHASSIS AND ENGINE »
Press oil into the system until the fluid runs out of the hole [6] in the master
cylinder without bubbles. Occasionally extract the fluid from the master cylin-
der reservoir to keep it from overflowing.
After you finish bleeding, remove the bleeder syringe, mount the bleeder screw,
correct the level in the reservoir and mount the cover (see above).
Fill the bleeder syringe [4] with a suitable fluid (see Technical Specifications
- Engine). Remove the bleeder screw from the slave cylinder [5] and mount
the bleeder syringe.
4
5
6
1
2
3