1999-2002 TRX400EX Fourtrax Service Manual, Page 230Get this manual
IGNITION SYSTEM
IGNITION SYSTEM INSPECTION
NOlE: Ifno spark jumps at the plugs, check all connections for loose or poor contact before measuring each peakvoltage Use commercially available digital multimeter (impedance 10 MDDCV minimum)The display value differs depending upon the internal impedance of the multimeterConnect the peak voltage adaptorto the digital multimeter, or use the peak voltage testerTOOLS Peak voltage tester (U.S.Aonlyl or Peakvoltage adaptor 07HGJ -0020100(not available in U.S.A with commercially available digital multimeter [impedance 10M!)1 DeV minimum)
DIGITALMULTIMETER
PEAK VOLTAGE ADAPTOR