Help! Bike keeps quitting on me

[JLov]

i just finished rebuilding my 80' xs650 a couple of months ago, this is my first build and bike and am new to all of this. First since i have had it finished the bike has ran great no problems. Then yesterday all of a sudden it died on me figure the battery had died. The screw to the negative cable came loose so i tightened it and charged the battery started fine. got out to ride it it died on me again this time while riding was losing power while giving it gas and kept feeling it wanted it stall and sounded like it kept backfiring. Got it started up again did the same thing while riding but this time trying to start it up again my battery got low and the light went very dim and it wouldnt turn over. So im very confused what it could be. Battery? charging system? another electrical issue? or fuel filter anything with the gas?

somethings about my bike

the engine is Not rebuilt
brand new carbs installed with new fuel filter
k&n pods
everything is stock besides the wiring harness which i ordered a new one from mikes xs

anything would be helpful

thanks guys,
josh

 

[funky]

this could be many things if the carbs are new dont mess with them sounds like charging system and mybe bad spark or electrical have you got point or electronic ignition.
Start with charging system make sure that your carbon brushes on the stator are ok then work from there. regulator rectifire check it all...
is your fuel new and clean is the tank clean are the carbs jetted right this is all the questions that need to answered is the pet cock in the right position. check everything ..
All the best Funky

 

[XSLeo]

Your 80 should have the stock TCI for ignition. It sounds like you have a similar problem that most have. The magnet in the rotor has gotten weak enough it can't trigger the pick ups.
One easy test of this is to fully charge the battery, then unplug the reg/rec connector. his disables the rotor so it won't create a magnetic field. If your bike then runs ok, it means the magnet is weak.
With the reg/rec plugged in it sends power through the rotor and creates a strong magnetic field to excite the stator into making power. This strong magnetic field over powers the weak magnet so the pick ups can't read it.
Easy fix though. Radio Shack sold a 3/16, 4 mm rare earth magnet that you just glue on top of the magnet in your rotor with most any epoxy you like I like the regular JB Weld, not the Quick Set, the Quick Set is not as strong or heat resistant.
Checking the charging system is a good idea too, just to be sure it's up to snuff. The TCI doesn't like low voltage. On mine even with voltages above 12.5 volts was too low to run well.
Leo

 

[XSLeo]

Just went to the Radio Shack site, those magnets are #64-1895, two pack, $2.99.
Leo

 

[rainycity]

I would check under the seat also. Mine did that and what happened was the
seat was I guess grounding out the fuse box. After a few times of it dying in the middle of a ride I noticed the neutral light wasnt coming on and the battery was getting low when I tried the electric start. But then after pulling off to the side of the road once I reealized (by accident) could wiggle my ass a little and it would light back up and start fine.
But anyways I went in and isolated it from the seat but since then my battery stays charged, the neutral light stays on and the bike hasn`t died since.