tci bike running and charging with the battery unhooked?

[joe-wiseguy]

i have a customers bike here that i built for him last year. strangley enough it will run without the battery hooked up after starting. it is an 82 street tracker. tci charging and ignition system. hook up battery, turn on switch, kick start. runs great. turn of key switch keeps running. unhook pos and negative terminals and still runs strong. you can hop on and ride with the lights burning bright. revs through the ranges great. so i bump stop the motor in gear with the brake and clutch. off it goes.

has anyone here ran into this scenario in the past? wtf? this is operating like a magneto system.

has standard tci box, regulator, tci stator and alternator system. i am sure someone here at this forum has ran into this before but i am stumped.

 

[jamesgs4]

off the top of my head, I think the red wire coming off the reg/rec is wired through the ignition switch, when it needs to go directly to the battery instead. It should not be connected to any brown wires, brown wires are switched at the ignition.

 

[littlebill31]

The red comes out of the battery to fuse, splits, one to reg/rec and one to the ignition switch. Then the brown comes out of the ignition switch to stator/rotor, then to reg/rec, then picks up the r/w. Both Br and r/w go to fuse. Out of fuse the r/w goes to the kill switch, then out of the kill switch to the TCI, then to coil. Brown goes to the signals and such.
That's for a stock bike.
I have mine like this to simplify it.
Pretty basic design

 

[joe-wiseguy]

thanks both of you. i have not changed out the stock harness. all the clips are stock and in place. i have removed the key switch and replaced with a toggle is all. ill check what james said too.

 

[littlebill31]

Here's a '82 diagram. It's the same as the '81description I stated.

 

[XSLeo]

The books say that to test the alternator you start the bike, unplug the mainfuse, test for voltag from the alternator side of the fuse. Evertime I tried that the bike justy died. I guess my rotor had no residual magnetism to keep the alternator making power. Yours must have some residual magnatism.
If the bike stays running with the main switch off, the engine stop switch off, then you have wiring problems.
Leo

 

[joe-wiseguy]

thanks again. i have all the factory service manuals. i am looking thru it all. freaking me out. i will just have to dig deeper. thanks again all.

 

[littlebill31]

When I rewired my first bike, I messed up a little. The bike, once running, would not turn off, lol. Key or kill. Plus it raced the engine to about 7K becuase the throttle stop was not adjusted right. That scared a little pee out.

 

[joe-wiseguy]

well i couldnt find anything wrong with the harness.... untaped it completely and checked all trails. this unit doesnt excellerate but runs perfect without the battery. hell i can hop on it and ride it off. i got tired of messing with it and installed a kill switch on the bars. i told my customer he needs one anyway. the red wire from the reg was not tied into the brown ignition either... it is a mystery... thanks to you all for helping.

 

[mrriggs]

well i couldnt find anything wrong with the harness.... untaped it completely and checked all trails. this unit doesnt excellerate but runs perfect without the battery. hell i can hop on it and ride it off. i got tired of messing with it and installed a kill switch on the bars. i told my customer he needs one anyway. the red wire from the reg was not tied into the brown ignition either... it is a mystery... thanks to you all for helping.

Does it have a factory regulator/rectifier, or has it been replaced at some point? If it's not a factory part then there may be an internal diode bridge that feeds the field directly from the rectifier. In that case you would need to add a diode inline with the brown wire to prevent it from backfeeding the ignition. Or just try a different reg/rec.

 

[CDNTX650]

i had a cb500/4 that did that....never did figure it out. I rewired it too. but i have rewired all of my other bikes and never had the problem...

 

[joe-wiseguy]

the regulator is stock. i thought maybe an issue was there too. so i swapped out regulators, cdi box, and coil. no change. i figured what the hell? couldnt find the problem so i installed a kill switch on the bars and interrupted the coils so i could stop this beast. it is something that someone else did in the harness or a glitch from the factory maybe.... i went and found my paperwork on the bike when i originally purchased it. checked my notes and seller comments i wrote down...the previous owner said that it was a great runner with awesome compression and good lower end. of course they all say that when selling. but he made a comment that it ran so good that it wouldnt stop running and laughed.... i made a mental note on his comment but didnt think he was serious. as the bike had no battery when he brought it over, i did a comp check and shifted it through the gears and looked over the title and made a deal with him. the bike sat for almost 2 years in my garage before i sold it to mike and built him a tracker out of it. so apparently this bike was doing the same thing with him. the mystery continues and i am moving on. i wish i knew how it worked as i could then turn a cdi bike into a magneto runner, now that would be the ticket. the bike is gone but i still ponder wtf about an alternator system running that way. thanks again to all for your input.

 

[resto]

Even though I haven't tried it myself, I don't think what you are seeing is that unusual. Basically it's acting the same as if you had a stone-dead battery or one that won't take a charge, after starting the bike with jumper cables for example. The alternator will put out enough power once the engine is running to supply the ignition and lights. It just won't start again after you shut it off.

I wouldn't recommend running it for a long time without a battery since the battery helps with smoothing out the voltage (less spiking) from the alternator. That will help protect your TCI and light bulbs.