KTM 250 SX 2010 User Manual (English)

Questions and Answers:

J
johnfosterAug 17, 2025
What to do if KTM 250 SX 2010 Motorcycle engine does not speed up?
- P
  pingramAug 18, 2025
  If your KTM Motorcycle engine does not speed up, it could be due to a few reasons. One possibility is that the carburetor is running over because the float needle is dirty or worn, in which case you should check/set the carburetor components. Another reason might be loose carburetor jets, so check/set the carburetor components. Finally, a fault in the ignition system could also be the cause, requiring you to check the ignition system.
S
Steven WhiteheadAug 21, 2025
Why does my KTM 250 SX 2010 Motorcycle engine have so little power?
- J
  Janet GarciaAug 21, 2025
  If your KTM Motorcycle engine has too little power, the issue could stem from several causes. A potential reason is an interrupted fuel feed, so check the fuel tank breather, clean the fuel tap, and inspect/set the carburetor components. A very dirty air filter can also restrict power, so clean the air filter. Inspect the exhaust system for leaks or deformation and replace the glass fiber yarn filling in the main silencer if it's insufficient. A fault in the ignition system could also be the culprit, requiring a check of the ignition system. Finally, inspect the diaphragm and reed valve housing for any damage.
K
Kathryn DunnAug 25, 2025
What to do if KTM Motorcycle engine stalls or pops in carburetor?
- A
  Audrey GomezAug 25, 2025
  If your KTM Motorcycle engine stalls or pops into the carburetor, it could be due to several reasons. First, ensure the fuel tap is in the ON position and refuel if the tank is low. Also, check the intake flange and carburetor for tightness, as the engine might be taking in bad air. Clean any loose or oxidized socket connectors or the ignition coil, and treat them with contact spray. Finally, check the cooling system for leakage and ensure the coolant level is adequate.
A
Amy Rice DDSAug 28, 2025
How to fix KTM Motorcycle engine overheating?
- J
  Joseph GonzalesAug 28, 2025
  If your KTM Motorcycle engine is overheating, start by cleaning the radiator fins, as they might be very dirty. If there's foam formation in the cooling system, drain the coolant and refill it. Inspect the cylinder head and cylinder head gasket for damage. Check for any bent radiator hoses and replace them if necessary. Lastly, adjust the ignition if the incorrect ignition point is due to a loose stator.
M
Melinda LewisAug 31, 2025
Why KTM Motorcycle engine has no idle?
- J
  Jacqueline AndrewsAug 31, 2025
  If your KTM Motorcycle engine has no idle, the possible reasons are the following: * Idling jet blocked, so you should check/set the carburetor components. * Adjusting screws on carburetor distorted, so you should adjust the idle speed. * Spark plug defective, so you should change the spark plug. * Ignition system defective, so you should check the ignition coil and the spark plug connector.
D
dhessSep 3, 2025
Why is my KTM 250 SX 2010 Motorcycle emitting white smoke?
- J
  jamiechanSep 3, 2025
  If your KTM Motorcycle is emitting white smoke (steam) in the exhaust gas, it could be due to a damaged cylinder head or cylinder head gasket. Inspect the cylinder head and cylinder head gasket for damage.
E
eileenmccartySep 7, 2025
Why is gear oil coming out of the vent hose on my KTM 250 SX 2010 Motorcycle?
- M
  Michael DawsonSep 7, 2025
  If gear oil is exiting at the vent hose of your KTM Motorcycle, it is likely because too much gear oil was added. Check the gear oil level.
R
Renee MckaySep 10, 2025
How to fix water in the gear oil of my KTM 250 SX 2010?
- T
  Tamara RangelSep 10, 2025
  If there's water in the gear oil of your KTM Motorcycle, it could be due to a damaged shaft seal ring or water pump. Check the shaft seal ring and water pump.

KTM 250 SX 2010 Specifications

General

Displacement	249 cc
Bore x Stroke	66.4 mm x 72 mm
Cooling System	Liquid-cooled
Transmission	5-speed
Rear Suspension	WP Monoshock
Front Brake	Single Disc, 260 mm
Rear Brake	Single Disc, 220 mm
Seat Height	992 mm
Ground Clearance	385 mm
Fuel System	Carburetor
Ignition	Kokusan
Starter	Kickstarter
Front Tire	80/100-21
Rear Tire	110/90-19
Wheelbase	1475 mm
Engine Type	Single Cylinder, 2-Stroke
Front Suspension	WP USD Fork, 48 mm
Fuel Capacity	7.5 liters