2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 205Get this manual
Ignition and ignition control system Ignition coil resistance: Primary coil: Red (R) Blackwhite (BW) 1.532.07 at 20 (68 F) Secondary coil: 12.49516.905 at 20 (68 F) 3Measure the pulser coil output peak voltageReplace the stator assembly if below specification Checking the ECM
1Disconnect an ignition coil coupler2Connect the test harness (2 pins) to the ignition coil3Measure the ECM output peak voltageIf below specification, measure the pulser coil output peak voltageReplace the ECM if the output peak voltage of the pulser coil is above specificationS6D88080
NOTE: Do not loosen the pulser coil screwDigital multimeter: YU-34899-A Peak volt meter adapter: YU-39991 Test harness (3 pins): YB-06791 Pulser coil output peak voltage: Whitered (WR) Black (B) Whiteblack (WB) Black (B) rmin DC Unloaded Cranking 3.6 3.4 Loaded 1,500 18.2 3,500 34.3