Recently, my trusty steed (the VFR) has been anything but “trusty”. After a great ride through the Victorian hills it abruptly decided not to start. The all too familiar “chugging starter motor accompanied with the dash going dim followed by the clock resetting to 1:00am” of a flat battery greeted me. Given that the battery would be approaching the five year mark, I thought nothing of it and replaced it.
Five engine restarts with the new battery later and I was left staring in disbelief as the dash again went dim and the clock went back to 1:00am. Sidenote: Why is it that Honda insists on making the clock so impossible to set without uttering profanities? When pressing two buttons at the same time means AT EXACTLY THE SAME TIME!
After coaxing the battery back in to a reasonable state with a charger it was time to whip out the multimeter and perform some testing. The simplest test from the workshop manual consists of running the engine at 5000RPM with the lights on high beam and measuring the voltage across the battery terminals. The manual rather cryptically suggests that the charging voltage should be more than the battery voltage “at rest” and less than 15.5 volts. Given that it was slightly lower than before commencing the test, it seemed a fairly safe bet that the bike was no longer charging the battery.
Back in the day, “they” used to say that Hondas were notorious for cooking regulator/rectifiers. My first Honda (the mighty Super-blackbird – the bike that was ever so briefly the fastest production model motorcycle on the planet) certainly managed to break this component and overcharge the battery in the process. It appears that Honda beefed up this component as my next Honda (a 929 Fireblade) burnt out the stator coil. It was looking like the VFR had suffered a similar fate.
The workshop manual specifies various tests – measuring resistance and testing continuity of various connections to determine the faulty part in the charging circuit. On the right hand side of the motorbike is the connector from the stator into the charging circuit. It is described as being a “3P natural connector” although “white” seems to be an equally suitable term…
According to the manual, there should be no continuity between any of the three yellow wires (in the plug) and ground. The multimeter revealed that two of the three wires did indeed have continuity to ground and hence I had found the problem! As for what to do about it, well that is a story for another time.