Why do i have to open full throttle when i start my bike?

[ahbai]

Im riding cbr400. Also need to open my throttle to start my bike:( maybe engine too old le.

[ChaoPuzzy1968]

your "choke" if you got one is it back in the proper position?

[Joe_Boxer]

Well, im not pretty sure abt 4-stroke bike as im riding a 2stroke bike bt i cn share a few issues regarding 4stroke prob:

 

BIKE WON'T START AFTER A CRASH HEAVY USAGE/ENGINE TEMP. HIGH

 

Pilot too lean

 

Idle set too high

 

Improper starting procedure

 

Bike wants hot-start button (KTMs and 400Fs)

 

BIKE RUNS ON OR WONT IDLE DOWN WHEN THROTTLE IS CHOPPED

 

Idle set too high

 

Air leak in intake or engine

 

Pilot too rich (when bike is hot)

 

BIKE WONT START WHEN COLD OUTSIDE

 

BIKE SPUTTERS/WONT CLEAN OUT AT HIGH RPM

 

Main jet too rich

 

Air filter over-oiled

 

Spark plug has debris on electrode

 

BIKE COUGHS & STALLS IN SLOW TURNS

 

Pilot jet too lean

 

Idle set too low

 

Valves set too tight

 

Decompressor is set too tight, so turning the bars engages release slightly

 

BIKE HESITATES OR BOGS OVER DEEP WHOOPS OR G-OUTS

 

Float level too low

 

Carb vent tubes blocked

 

Main jet splash shield not installed

 

Float level too high, gas is trapped in vent tunes (install T-vents)

 

BIKE STARTS BUT WONT TAKE THROTTLE WITHOUT SPUTTERING

 

Pilot jet too rich

 

Water in fuel

 

Debris in main jet

 

BIKE SUDDENLY STARTS SPUTTERING/GAS FLOWS FROM VENT TUBES

 

Stuck float check valve

 

Debris in gas or carb

 

BIKE RUNS HOT/FEELS SLOW & FLAT ON STRAIGHTS

 

Main jet too lean

 

Fuel octane too low, causing detonation

 

BIKE COUGHS & STALLS WHEN YOU WICK OPEN THROTTLE

 

Needle too lean

 

Slide cutaway too lean

 

Pumper circuit blocked or too lean

 

Lastly,

To re-emphisize: If the idle never drops when you're turning the fuel screw in, you need a smaller pilot jet. If the idle never drops when you're turning the fuel screw out, you need a bigger pilot jet.

 

**Hope it helps**