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1985 fxstc problem maybe solved. MAYBE, please read

ron1978

ron1978

Active Member
a while back my dads 85 softtail started running little rich, then he thought the carburator started acting up, during last weeks ride his bike was running really good then all of a sudden he gave it 3/4 throttle and it started popping and black smoke , the bike will idle great and crank great but will not take gas under load,,, so we order rebuilt carb... while replaceing the newer carb i noticed and told dad , look your ground cable is broke on your frame going to your battery, so my question is this??? what all was affected while the ground cable was arcing?? like coil, points?? anything. would the broke cable cause all this problem?? ( what i'm saying is what all was not working correctly)

i have not got ground cable fixed yet and he'll get the carb put on first to see if it fixed it, but i thought i'd ask what all you guys think would have it affected while it was arcing. thanks
 
my thought where like the coil fire, and such?

i asked him about the black smoke, he said the barb was already running little rich anyway, and we think it may have a crack in the intake somewere, the bike feel over on the side while he was washing it about months ago . but the poping i believe is coming from the broke ground wire, any thoughts on this is appreciated
 
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Ron, Do you know if that is the only source to ground that the battery has. By that I mean, is there only 1 cable from Battery Negative to grd. Sometimes right at the negative pole of the battery there will be more than 1 wire, a heavy wire along with a lighter gauge wire. Was the cable completely broke off? It was not even held on by a few strands of wire?

I am amazed you were able to draw enough current to spin the engine & start it.
 
only one wire to frame, but i have a idea that his solo seat was acually setting close or on the ground side on battery causeing it to bleed through the seat it self for a ground since it lost it ground to frame, he said about a month ago he turned the switch and the lights flashed and went dim, but they picked right back up like it was a relay, but we know now it was the ground broke, and it was having hard time cranking , it sounded like it was not getting enough juice to starter.

he said that ground wires been on that bike for 24 years, it wasn't corroded, looked like it was over torqued and made the lug thin,
 
Well if that is the only source to Ground the battery had, & the cable was completely broken off & the seat was completing the circuit path,,,,
I would say that condition would raise havoc in the complete electrical system.
All sorts of problems could arise from that. Your lucky that bike is pre-ECM technology (guessing it is).
 
i think it is, its a simple looking setup, points, coil , plug wire and carb, it has a funky style carb on it also a non cv kehien carb, they used this carb on the earlier models and can't hardlt find any aftermarket things that fit it.

we have already bought a rebuilt carb, and new intake with newer screaming eagle breather, thining that the new carb would fix the popping , since it started here recently.
, i think the broke wire has everything to do with it now,
 
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I would not even wait to see if the carb fixes it. The effects of an electrical connection like that are hard to duplicate. I would just get that cable replaced and clean up both battery terminals.. Suddenly loosing engine power while in a heavy turn can cause you to drop a bike.
 
A bad ground can cause intermittant/weak ignition and since all electrical accessories rely on that ground cable return...it likely was the problem you had. And as Hoop says, if you are in a tight turn, intermittant ground could cause ignition/power loss instantly, almost as quick as loss of fuel and cause you to drop the bike. Really want to clean the connection, scrape and clean it with contact cleaner/alcohol and use dielectric grease to prevent corroision due to water and oxgen intrusion.
 
ron1978 said:
a while back my dads 85 softtail started running little rich, then he thought the carburator started acting up, during last weeks ride his bike was running really good then all of a sudden he gave it 3/4 throttle and it started popping and black smoke , the bike will idle great and crank great but will not take gas under load,,, so we order rebuilt carb... while replaceing the newer carb i noticed and told dad , look your ground cable is broke on your frame going to your battery, so my question is this??? what all was affected while the ground cable was arcing?? like coil, points?? anything. would the broke cable cause all this problem?? ( what i'm saying is what all was not working correctly)

i have not got ground cable fixed yet and he'll get the carb put on first to see if it fixed it, but i thought i'd ask what all you guys think would have it affected while it was arcing. thanks
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would be willing to bet that is the cause of the problem. I have ran into this before and that was it put a new ground cable on and it will fix it
 
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