Yamaha YZ250FM 2021 Owner's Service Manual

THROTTLE BODY7-8b. Remove the fuel tank bolt and lift the fueltank.c. Disconnect the fuel hose from the fuelpump.Refer to “REMOVING THE FUEL TANK”on page 7-2.WARNINGEWA19380Cover the fuel hose connection with a clothwhen disconnecting it. This is because re-sidual pressure in the fuel hose could causefuel to spurt out when the hose is removed.NOTICEECA24750Make sure that the fuel hose is disconnectedby hand. Do not forcibly disconnect the hosewith tools.d. Connect the pressure gauge “1” and thefuel pressure adapter “2” to the fuel hose.e. Start the engine.f. Measure the fuel line pressure.Out of specification  Replace the fuelpump.EAM30273ADJUSTING THE THROTTLE POSITIONSENSORWARNINGEWA15950• Handle the throttle position sensor withspecial care.• Never subject the throttle position sensorto strong shocks. If the throttle positionsensor is dropped, replace it.1. Check:• Throttle position sensorRefer to “CHECKING THE THROTTLE PO-SITION SENSOR INPUT VOLTAGE” onpage 8-50.2. Adjust:• Throttle position sensor anglea. Connect the Yamaha diagnostic tool.Refer to “YAMAHA DIAGNOSTIC TOOL”on page 8-15.b. Temporary tighten the throttle positionsensor.c. Check that the throttle grip is fully closed.d. Connect the throttle position sensor to thewire harness.e. Set the Yamaha diagnostic tool to “diag-nostic mode”.f. Choose the diagnostic code No. “01”.g. Adjust the throttle position sensor mount-ed angle until “11”–“14” appears on theYamaha diagnostic tool.h. After adjusting the throttle position sensormounted angle, tighten the throttle posi-tion sensor screw “1”.Pressure gauge90890-03153Pressure gaugeYU-03153Fuel pressure adapter90890-03186Fuel pressure adapterYM-03186Fuel line pressure (at idle)300–390 kPa (3.0–3.9 kgf/cm²,43.5–56.6 psi)1212Yamaha diagnostic tool USB (US)90890-03269Yamaha diagnostic tool (A/I)90890-03264FI diagnostic tool sub–lead90890-03212FI diagnostic tool sub–leadYU-03212OBD/ GST Leadwire kit90890-03249Throttle position sensor screw3.5 N·m (0.35 kgf·m, 2.6 lb·ft)T R..1