Units 1&2 Baruch Park

Viro Crescent, Stikland

021 910 0535


Mon - Fri: 9:00 - 17:30

Sat - 9:00 - 13:00

David’s Story – Regulator Problems

This week appears to be voltage regulator problem week in our workshop. For those less technically astute I will explain, the voltage regulator on a motorcycle is an electrical black box than ensures a steady 12-14 volts is delivered from the motor to the bikes electrical system while the motor is running. If this box is not working correctly, either no power with be delivered, which will result in the battery running flat and the bike stopping, too much power, the battery is then cooked and worse still, possible damage to other electrical components on the bike, the ECU for instance, expensive!

This week we have a Triumph Tiger 955 and my own Cagiva Raptor 1000, not charging correctly, and both with suspected aftermarket, Chinese, regulators. Which has reminded me of an amusing story about David’s Honda X4 and its failing regulator.

The X4 is an unusual motorcycle in SA being only made for the Japanese home market between 1997 and 2003, a big 1300 4-cylinder motor in a low-slung frame, solid rear wheel and stubby large chrome exhaust, I believe, produced to compete with Yamaha’s V-Max. Anyway, somehow a few escaped Japan, most ending up in Europe, mainly Holland, but a few also made it here, and by some strange coincidence David and I both own one, mine’s in the picture below, or above.

Ok, background over, now the story. David and I often ride together, he always on his X4 and myself on a variety of bikes. Back mid 2019 we went for a Wednesday ride, out around Paarl rock and then back through the Cape Farm lands, nice smooth flowing roads without much traffic so we were making, shall we say, good progress. I was on my White Ducati 900, important for later, and David as always on his X4, we get to Klipheuwel, on our way to Philadephia and the Pepper Tree for lunch, when the X4 stops, no electrics. We remove the seat hoping for a loose connection or something easy to fix, no such luck, the battery very hot, bloated and is kind of steaming, acid stream, bit like me after a good curry, not good.

We trailer the X4 to the workshop, test the charging system, and get 18 volts coming out of the regulator, which is obviously defective and has ruined battery, thankfully no damage to any of the other components. A new Honda regulator for the X4 is very expense and takes time to obtain, so, David decides to purchase an aftermarket regulator, with the correct number of wires, from someone he knows at a good price. We fit this and a new battery and all is good, bike producing the correct 13.5 volts and charging perfectly, David is happy.

Two years later David and I are out riding with some other guys, and for the first time since the X4 broke down, I am on my White Ducati 900, again. Stopped at traffic lights, robots, David leans over and shouts “Remember last time both these bikes were to together mine broke down”, yes, I laughingly reply. We continue into Muizenberg and at the next set of robots the X4 stops, no electrics. David is incredulous, how can this happen again, it’s your fault for bring that bloody Ducati!

We trailer the X4 to the workshop. Now it gets interesting I charge the battery and get the motor running, then, before doing anything else I check the output from the regulator, zero, nothing, no volts. I remove the regulator from the bike, restart the motor and check the stator output. The stator is the part that does the actual generation of the electricity, small wire coils in a ring around a moving magnet, normally mounted on the end of the crankshaft. The stator checks out fine, a nice 50+ volts across all three wires. Then just to ensure the problem is not a bad connection, I refit the regulator and check its output, suddenly its pumping out 18 volts, battery boiling power, switch off quick. Now, why should a regulator change from producing nothing to producing 18 volts, good question, answers on a postcard to the usual address please.

This time we find a more compatible Suzuki regulator, to replace the aftermarket one. I suspect the Chinese aftermarket regulators are made for the smaller motorcycles with motors that don’t produce the electrical power that larger motors do. They work, but probably the extra power causes them to run hotter thus shortening their working life.

David is happy again, but obviously his X4 doesn’t like my White Ducati, and I have been warned not to bring it again. Strange really, as my X4 parks close to the Ducati in my garage and that one does not seem to mind. Makes you think, does it not.