No Spark- questions

[briguy66]

1980 SG: Bike died while on ride, found bad coil and replaced w/used OEM. Wasn't running good, (hesitation-sputter on acceleration) so was synching carbs when it just died. After much fiddling w/carbs, found I had no spark at any cylinder. After many hours checking ign coils, pickup coils(incl re-do on wires) and field coil/stator, all fuses, swapping out ECU (used) and checking every wire and connection for continuity and/or power ,+ all grounds and added regulator extra ground too, (all good). I admit I'm stumped even tried a new plug for spark test and nothing.

Q#1: no power w/key on at ECU connection for the Bl/wh wire from tip-over switch but good continuity thru it and wire to/from ECU too. Normal? I think a ground? has continuity to ground anyway.
Q #2: Ohm readings are all marginal, ie, stator coils Wh wires are .6, brown coil wire to green coil wire is 3.7, Pickup coils 730, ign coils in spec on primary and 15 on secondary (w/o the 5ohm ea caps on) for total of 25ohms cap-cap). Could all these marginal components lead to NO spark at all? For comparison I tried my xs750 and it had similar not-spec readings but it runs fine.
Ideas?

[natemoen]

What is your battery voltage? Under about 10.5 volts the tci can't function.

Do you have power at the ignition switch?

[briguy66]

No Spark- questions

1980 SG: Bike died while on ride, found bad coil and replaced w/used OEM. Wasn't running good, (hesitation-sputter on acceleration) so was synching carbs when it just died. After much fiddling w/carbs, found I had no spark at any cylinder. After many hours checking ign coils, pickup coils(incl re-do on wires) and field coil/stator, all fuses, swapping out ECU (used) and checking every wire and connection for continuity and/or power ,+ all grounds and added regulator extra ground too, (all good). I admit I'm stumped even tried a new plug for spark test and nothing.

Q#1: no power w/key on at ECU connection for the Bl/wh wire from tip-over switch but good continuity thru it and wire to/from ECU too. Normal? I think a ground? has continuity to ground anyway.
Q #2: Ohm readings are all marginal, ie, stator coils Wh wires are .6, brown coil wire to green coil wire is 3.7, Pickup coils 730, ign coils in spec on primary and 15K on secondary (w/o the 5ohm ea caps on) for total of 25K ohms cap-cap). Could all these marginal components lead to NO spark at all? For comparison I tried my xs750 and it had similar not-spec readings but it runs fine.
Ideas?

[motoman]

Your wacked readings don't necessarily condem conponents. Got several bad connections and groundings sounds like.

May wanna start with cleaning ignition switch internally, then move on to removing AND disasembling kill switch...toss ALL pieces including switch into some EvaporRust and clean them up. May be surprised at the results of your testin' afterwards. Goes for every other plastic plug-in you find on harness too.........

[briguy66]

Battery is at 11.6 V. New AGM battery this year, run down from trying to start. I'll charge it back up to 12 and try. Power to ign switch? dash lights/neutral, etc all on--signals, brake lights, horn etc all work when switched on.

[3Phase]

briguy,

A #1) The Black/White wire goes to the Tip Over Switch from the TCI and it is a ground. It's normally not grounded but when the bike tips over more than 60 degrees it grounds the TCI and kills the ignition. The engine will run just fine with the Tip Over switch unplugged but if you drop the bike or lay it down the engine will keep running.

A #2) The Ohm readings are a little out of whack but not that bad.

What's the voltage reading on the ignition coil Primary wires when the starter is cranking the engine? The Ballast Resistor is bypassed when the starter solenoid kicks in and there should be a full 12V on the ignition coil Primary side.

.

[TopCatGr58]

Hey Briguy,

First of all, bike DIED while running. When 1 ignition coil goes bad or dies, the bike will usually keep running on just 2 cylinders, not very well or very strong, but will keep running. Finding the bad coil may have been a red herring! As was hinted to by 3Phase, what's the battery voltage? If below 12 volts static reading, sounds like the charging system may have gone bad which drained the battery while riding down to below the ~10.5 V threshold that we've found will kill the TCI/ECU as you called it.

Charge the battery, test and if > that 12 volts, then start the bike, it should start, then test the voltage quickly while running, should be ~14.5 V at 2500+ rpm. IF still 12 or less, charging system not working, further diagnostics needed.

IF the bike won't start, monitor the battery voltage while cranking, it will probably be dropping to ~10.5 volts or so which means that it can turn the starter motor, but not have enough juice left to power the TCI...time for a new battery. But you can put a jumper battery onto your suspect battery and the bike will probably then start. Then test charging as described above.

T.C.

[briguy66]

electrical no spark

Charged the battery to 12.3 volts last night. Was at 11.9 tonight before I touched anything. Had 9.8 volts at ign coil primary while cranking and battery volts dropped to 10.7. I'll re-charge and try a jumper battery and see if I get spark. Found out the ECU I bought came off running bike so that eliminates it as possible cause.
New AGM battery, less that 200 miles on bike since purchase. Hope I saved that receipt!

Thanks for the help, i'll advise on outcome.

[briguy66]

Well, notwithstanding the condition and state of the battery and stator/coil, the mystery is solved. --- Tip-over switch--- It should NOT have continuity between terminals on it when correctly oriented in holder on bike. I had a spare and replaced it incorrectly. I just ASSumed it should have continuity! The rubber holder has arrows to indicate correct orientation but the actual switch housing has only a small arrow on back of it partially obscured by wire lead indicating correct position (Sure, NOW I see it...). Will maybe never know actual original reason for no spark condition but hey, im good with that....
This is why a guy needs AT LEAST 2 motorcycles if they are as old as our xs11's
Again, thank you so much for the input and support.
Brian

[3Phase]

Nice troubleshooting, Brian!

Here's a link to a post I made a few years ago with a couple of pictures of the switch so you can see how it works. Click the pictures to download a larger image:-

emergency shut off tip over switch: Easier to photograph than explain

.