1999-2004 Honda TRX400EX FourTrax Service Manual, Page 230Get this manual
IGNITION SYSTEM
IGNITION SYSTEM INSPECTION
DIGITAL MULTIMETER
If no spark jumps at the plugs, check all connections for loose or poor contact before measuring each peakvoltage Use commercially available digital multimeter (impedance 10 MOIDCV minimum) The display value differs depending upon the internal impedance of the multimeter
Connect the peak voltage adaptor to the digital multimeter, or use the peak voltage tester
TOOLS Peak voltage tester (U.S.Aonly1 or Peak voltage adaptor 07HGJ 0020100 [not available in U.S.A with commercially available digital multimeter [impedance 10 DCV minimum)
IGNITION PRIMARY PEAK VOLTAGE