1976 Suzuki GT550

Bertie Simmonds
April 26, 2017

Q: The headlamp bowl was rusty and my mate gave me a new chrome one. Foolisly, I accepted and removed the headlamp in order to replace it. As you may know, in the shell there is a huge tangle of plugs and wires which are squashed between the reflector and the back of the shell. Using wire and plug colours I reconnected all but one of the wires and everything works… except there’s no spark at the plugs! The remaining socket is black with one orange and one white wire. Could it be that there is a ‘spare’ socket or is the plug that fits it lurking somewhere that I’ve missed? I’m used to working on 1950s British iron and Jap electrics are something else!

Wire woes with a GT550!

A: The connector with just orange and white wires in it is for the front brake switch, so that cannot have anything to do with the ignition. The ignition circuit works like this: a red wire leads from a 20 amp fuse to the ignition switch. This powers an orange wire when the ignition is switched on, and as well as powering other circuits, this leads to the handlebar mounted ignition cut-out switch (and also the starter button) and hence to the three ignition coils. Does the starter work? If so, current is passing through the cut-out switch so you need to follow the wiring through from this point.

About the Author

Bertie Simmonds

As a child Bertie (well, Robert back then… blame his sister for the nickname) was exposed to motorcycles thanks to his uncles. They would show up at his house with a lovely lady as pillion throughout the 1970s and 1980s. After a naughty time on field bikes (it’s what we did back then) Bertie passed his test in the early 1990s and became a reporter for MCN in 1995, moving to the sports desk and covering World Superbikes in 1996. With a change to Bike Magazine in 1997, he stayed until 2000 as news, features and road test editor. Moving into PR with Cosworth, Bert was bored with cars and returned to bikes in 2001 with Two Wheels Only, becoming editor in 2002 and leaving to be freelance at the end of 2004. With almost a decade freelancing, Bertie joined Mortons in 2013 and became editor of Classic Motorcycle Mechanics, a post he’s desperately clung to, to this day. And no, he’s never had a pretty girl on the back of his bike.

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