LEFT KEY ON,NOW DOESNT RUN !!

Hello everybody, well hears the deal. went for a ride last week bike was running really pretty good
alittle rich no big deal, my bike is an 81 xs,so back to the story,I get home go in the house for
couple hours, go to put it away found that had left on the key,battery now dead pushed into garage
charged battery,now wont stay running, tried a couple more times same thing,yesterday tried to start the
bike, alittle twist, now got the bike started now its really running rough and the neutral is flashing on and off
so I think the battery is going dead,but I just charged it, the battery has 12.50 v on it,I walk away. So
today I try and start the bike, now I have no headlight,no neutral light.no starter, I have brake \ tails lights, turn signals, horn, so I walk away before I break something.
any ideas ?
any help would be great.
thanks bob in burbank

Leaving the key on can not only drain a battery but can kill one too. Some cheap or old batteries won't recover from being completely drained.
How old is the battery?
A new battery won't cost much.
Leo

About 6 months old, after sitting all night it was reading 12.50v.

does your voltage hold up when cranking the starter?

bultaco59 said:

Hello everybody, well hears the deal. went for a ride last week bike was running really pretty good
alittle rich no big deal, my bike is an 81 xs,so back to the story,I get home go in the house for
couple hours, go to put it away found that had left on the key,battery now dead pushed into garage
charged battery,now wont stay running, tried a couple more times same thing,yesterday tried to start the
bike, alittle twist, now got the bike started now its really running rough and the neutral is flashing on and off
so I think the battery is going dead,but I just charged it, the battery has 12.50 v on it,I walk away. So
today I try and start the bike, now I have no headlight,no neutral light.no starter, I WALKED AWAY
BEFORE I BREAK SOMETHING, any ideas ?
any help would be great.
thanks bob in burbank

Click to expand...

Hi bob,
You are not alone, I left my bike switched on for 3 days. Oh my, was it dead or what?
Here's a true story about that to make you smile.
Stuck it on my little 1Amp charger overnight and it was still dead in the morning.
Bought a new battery. Sat it on the charger as recommended to top it right up before first use.
During this I happened to check my 1Amp charger output. All of 8.5 Volts.
Snip snip with the sidecutters. Charger clips & wires in the parts drawer. Charger in the garbage.
Got out my other 1 Amp charger. Checked that it put out 14 Volts. Topped up my new battery and installed it.
Bike fired up and ran great. Expensive lesson but I'm back on the road, eh?
Then I put the working charger on my dead battery overnight.
Next morning the allegedly dead battery started the bike no problem. Gave the new battery to my son for his bike.
So, did you check that YOUR charger is actually putting out ~14Volts? If it is and your battery won't crank your starter
after being charged up it's likely that getting sucked totally flat has killed it.
Your battery may well show 12.5V after being charged but it ain't got no cranking Amps no more and it's new battery time.
But before you buy a new battery, make sure your old one really is the problem by boosting the bike from your car battery.
If the bike starts up good and revs nice while it's boosted but begins to act up when you take the booster cable clips off
you can be pretty sure your battery really is FUBAR.

but do not use a RUNNING vehicle for the boost! 12.5 is low for a fully charged battery a bad battery cell can look OK on a VOM but not generate any power to start run the bike.

Take your battery to Autozone, O'riellys or somewhere else where they will check it for free. Better yet, take it to more than one place to get more than one test to compare the results, free charging too. Then check the charging system with a known good battery.

Scott