KTM 400 EXC User Manual (English)

Questions and Answers:

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Benjamin RosalesAug 14, 2025
Why does my KTM 400 EXC Motorcycle engine get too hot?
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  Gloria StricklandAug 15, 2025
  If your KTM Motorcycle engine is overheating, several factors could be the cause. First, check and refill the cooling liquid, also inspect the cooling system for any leaks. Ensure there's adequate airflow while riding; consider retrofitting an electric fan if needed. Make sure the cooling system is properly bled and the radiators are clean. If foam is present in the cooling system, replace the coolant with a brand-name antifreeze liquid. Inspect cooling hoses for bends and replace if necessary. Check the thermostat for proper operation (opening temperature 70°C or 158°F). If you have an XC Desert model, check and replace the fan fuse if blown.
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Peter KelleyAug 18, 2025
Why my KTM 400 EXC Motorcycle engine will not reach full power?
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  Craig TrujilloAug 18, 2025
  If your KTM Motorcycle isn't reaching its full power, start by checking the fuel system and carburetor for dirt or blockages, and clean them if necessary. Replace the float if it leaks. Ensure the air filter is clean; if it's very dirty, clean or replace it. Inspect the exhaust system for damage and ensure it's tight; replace the glass fiber yarn in the exhaust silencer if needed. Also, check and adjust the valve gap. Finally, check the setting of the hand decompression cable.
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James TurnerAug 25, 2025
How to fix KTM 400 EXC Motorcycle when engine doesn’t crank?
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  Anna PerkinsAug 25, 2025
  If your KTM Motorcycle engine doesn't crank with the E-starter, the issue might be a blown fuse. To resolve this, dismount the left paneling and the filter box cover and replace the fuse in the starter relay. Another possibility is a discharged battery; recharge it and investigate the causes of the discharge. Also, ensure the emergency-OFF switch is turned on (Australia only).
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Joshua WashingtonAug 28, 2025
What causes a KTM 400 EXC engine to fail to idle?
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  Melissa MorganAug 28, 2025
  If your KTM Motorcycle engine fails to idle, the problem could be a clogged idling jet. Disassemble the carburetor and clean the jets. Also, the spark plug may be defective and require replacement.
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Miss Michelle AllenAug 31, 2025
What to do if KTM Motorcycle engine stops or splutters in carburetor?
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  Shane LopezAug 31, 2025
  If your KTM Motorcycle engine stops or sputters in the carburetor, it could be due to insufficient fuel. Clean and check the fuel system and carburetor. Also, check the rubber sleeve and carburetor for a tight fit, as the engine might be taking in air uncontrollably.
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jacobsloriSep 3, 2025
Why does my KTM Motorcycle have high oil consumption?
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  nicholasfloresSep 3, 2025
  If your KTM Motorcycle has high oil consumption, check if the hose of the engine ventilation is bent. If it is, dislocate or replace it with a non-buckling ventilation hose. Also, check the engine oil level and correct it if it's too high. If the motor oil is too thin, use a thicker engine oil.
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Melanie ChenSep 7, 2025
What to do if horn, flasher lights and E-starter do not work on KTM 400 EXC Motorcycle?
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  Angela BrewerSep 7, 2025
  If the horn, flasher lights, and E-starter on your KTM Motorcycle aren't working, it may be due to a blown fuse in the starter relay. To fix this, dismount the left side paneling and filter box cover, then replace the fuse.
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Kyle SmithSep 10, 2025
Why KTM Motorcycle engine does not rev high?
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  Scott EllisSep 10, 2025
  If your KTM Motorcycle engine does not rev high, the carburetor fuel level might be too high because the float needle valve is dirty or worn out. Dismount the carburetor and check if it's worn out. Also, tighten the jets.

KTM 400 EXC Specifications

General

Displacement	398cc
Bore x Stroke	89mm x 64mm
Transmission	6-speed
Fuel System	Keihin FCR-MX 39 carburetor
Front Brake	Single 260mm disc
Rear Brake	Single 220mm disc
Cooling System	Liquid-cooled
Starter	Electric starter
Rear Suspension	WP Xplor shock absorber