Cyl 2&3 misfiring With spark

Bike was running fine a few days ago, I start it up once a week wishing for warmer weather and it idols fine with choke on and off. This week it starts & runs fine but I left my charger on the battery all of a sudden I hear it start spuddering and missing with the exhaust smelling rich .
Tested both coils and they have good spark, pull 1&4 spark caps & bike won't start, pull 2&3 caps & bike will run. I'm thinking with the extra amps & voltage the charger was putting out some how damaged either my pickups for cyl 2&3 or worse it damaged the TCI.

 

Great looking bike !
You're not supposed to start them weekly, if you have a car size charger, you shouldn't just leave it on when running, and you're not supposed to just pull the plug wires and run it, the voltage stack-up can possibly hurt the coils.

If you "tested both coils and they have good spark" I'd assume the TCI is good. It can fail on one "channel" and to test that, you cross your coil supply wires (under the tank) and re-test. (then uncross them)

That brings us to a quick carb test;
While idling on 2 CYL, spray just a whiff of starting fluid into the opened airbox. Alternate test - dip an old paint brush in gas and insert it towards the center 2 inside the airbox. If the engine barks to life, you win a free carb cleaning ! Did you add StaBil ??

 

Thanks Time to Ride,
I was using a car charger with 6 & 12 Volt settings on 6V start or 12V 2 amp or 10 amp max nothing higher. The battery is bad and won't hold a charge, I plan on replacing it come spring. That was the only reason for the charger being used.

I replaced both coils early September, 2&3 coil was bad. When testing for spark I used a spark tester for each lead, first attached to spark plug then grounded to cylinder head.

As for the TCI, I have not yet swap channels on the coils. I was thinking if I had good spark coil 1&4 as well as 2&3 swapping the channels would not matter, but I will give it a try.

My problem may be fuel related, would having two carbs 2&3 going out at the same time be likely?

I have nothing but free time on my hands so I guess it is time for me to break out the service manual heat the garage and get the work.

 

TimetoRide,

Just spent a few mins in the garage pulling the plugs & sure enough plugs 2&3 were fouled & gas soaked. Cleaned all 4 reset the gap & presto.... I'm firing on all 4 cylinders. I guess having the charger hooked up to the bike while running made me jump to the conclusion that I had missed something up with either the charging or ignition systems.

Valve adjustment, carb cleaning and sync is on my "for my peace of mind" list, the bike runs great though but I have wanted to polish the carb bodies. I have never looked foward to rebuilding any carb ever.... small engine, ATV, motorcycle, car.

 

you didn't happen to replace the wires and caps when you replaced the coils did you?

ya know there are resistors in caps and the ones in the 2&3 are higher rating than the "outside" ones...

just tossing thoughts into the ongoing conversation that will be your patch up.

BEAUTIFUL Seca

 

The stock caps were put on the new coils, with my intention of eventually replacing them with 0 resistance caps and running 5k resistance plugs.

 

replace the battery. Some battery chargers omits the same frequency as the pick up coils send and will cause misfiring. Sounds strange my virago did that never herd of it before. I replaced coils tci pick up coils even ran new wires to the coils from the tci. One day i thought i would try jumping it off a weak car battery it worked perfect. The symptoms i had were as soon as you bumped it over it would spark continuous even when you let up on the starter button tach would show 7k soon as the key was turned on . It might not be your problem but if you don't replace it and keep running it your gonna need a stator. Weak battery is #1 cause for stator failure

 

I have a good news bad news scenario for the battery.
It has a two year free replacement warranty of which one year has passed (good news)
I can't find my damn receipt (bad news).

I do believe I will be in need of either a stator replacement or voltage regulator/rectifier. I put my good ATV battery in and checked running voltage 13.52V at 2500 - 3k RPM, higher rpms = no better output.
Voltage range should be 14.5 +or- 0.3

What was strange is that volt output rose when I turned on a bike load.
Aux. light, turn signal & brake light my voltage silghtly rose 13.7v, 13.8v, 13.95v more loads more output.

Once I replace the battery I will retest everything unless someone has some insight on this.

 

I see the spammers are back

 

Fantastic you da man

 

that's how the sy stem works. the heavier the load the higher the voltage.

with the stock equipment. couldn't say what added accessories would do.

generally when testing the bike it should be the way it was originally manufactured. if the headlights are supposed to be on. that's how you test. otherwise you won't get the correct readings.

i haven't looked at my suzi to see if it works the same way. but all my 1980's bikes worked that way. pulled the fuses and voltage dropped. don't know what my early 1970's bikes did either.

you get 13.93 volts with everything that's supposed to be on. your not far from the money. a fresh battery will reveal the real story though.