Wiring Problems

Hi..Newbie here...Ok guys...Bought a bobber, its a XJ550 seca 1982...looks lovely, new parts all over it, really stands out..BUT BUT....it wont start..at all !!!!!!!!....The engine turns over no prob but when I checked to see if it was sparking...it wasn,t..Could the prob be....1. Right hand side cut off switch not wired correctly..2 left hand switch is NOT original ??? 3 coil problem, 4 wiring to coils....Im lost !!!!.. any help would be great thanks

 

Hi Gazz, I'll wade into your waters of unknown.

First, congrats.

Now, the ugly parts. You're walking into a field of previous owner's ideas, good, bad, and ugly. So be prepared to learn a LOT about your bike's guts.

Bike electrical systems aren't super complex, and can be figured out with perseverance and patience. Get yourself a manual or wiring diagram and start following the voltage. In basic terms, power has to flow through all your stuff, doing other stuff, for spark to happen. BUT, seeing as how the previous owner (PO) bobbed it, your wiring may be frankenstein'ed a bit, so detective skills will come in handy here. Along with a trusty meter. Cheap ones can work, but I've been lied to before by a cheap meter.

A few helpers: the kill switch ( right side control block ) will disable the starter from working, so if you're getting the motor to turn over, the kill switch is working. I don't know what's on the left side, as usually it's the brights, turn signals, and horn. If you have a kill switch over there too, then you may be in for a VERY interesting investigation.

Now, coil, yes, this could be bad. but usually both aren't bad, so you may want to check all 4 to see if the other coil is working ( there's 2, i think, both handling spark for 2 plugs ). You may also want to try new plugs, as they could be bad too.

I'm sure there's other things to be aware of and try out, but that should get you going, and hopefully others can chime in here as well.

Good luck.

 

Try to compare what you have to the absolute basics:

 

If the motor is turning over but not sparking (for sure no spark, not fuel issues) then the most common cause is simply a weak battery.

The ignition system in our bikes simply WON'T FIRE the plugs if it's not getting enough current. It's quite common for there to be enough left in the battery to quite rapidly spin the motor and have nothing left over to power the ignition.

Install a BRAND NEW SET of NGK D8EA plugs (proper for the 550) and be sure the battery is FULLY CHARGED and you should at least get "fire."

If it's letting the motor turn over, it's not a "safety circuit" issue.