1996-2005 Suzuki DF40, DF50 Four Stroke Outboard Service Manual, Page 373Get this manual
13-37 DF40DF50 "K1" (01) model (3) Connect the tester probe(Red) to each terminal(Voltage)
Injector No.1 No.2 No.3
Terminal No40 39 38
(4) Crank engine and measure voltageFuel injector operating signal10 V
A Peak voltage reading (NEG) 0V level for peak voltmeter
FUEL PUMP SECOPERATING SOUND Turn ignition switch ON and check for fuel pump operating soundFuel pump operating soundSounds for approx3 seconds only