is the battery shot?

[HCR250X]

I just rebuilt my 400ex and put a stage 2 hotcam, and 10.8:1 JE 416 piston. It started right up when we first put it back together and ran bueatiful. Then it wouldnt start the next day so we checked everything over, timing, compression, spark, weverything was fine. I gave up on it for a couple weeks because It was like 0 degrees outside and I dont have heat in the garage. I went out there yesterday gave it some ether, and got nothing. Then I hooked the 12 volt battery charger on it, and it turned over once and fired right up. Ran bueatifully and astarted fine everytime after that. Then I went out there this mourning and it wouldnt start, and the battery started going dead so I hooked the charger up to it and it turned over once and started right up. My question is could this mean my battery is shot, or is there something else electrically that would cause this?

[Pappy]

chances are the battery is discharged to the point it will not readily accept a charge.

try removing the battery, charging at 2 amps for 3 hours. let the battery sit for 24 hours then re charge for 1 hour at a 2 amp setting. if your using an automatic charger your just going to have to live with the charging cycle it will give you but if you have a manual charger follow what i have posted.

if after the charging cycle, you still expierence battery trouble, id say its shot....but chances are you will be ok.

[HCR250X]

Ok I tried charging the battery like you said but the quad will still not start unless I hook the charger up to it. Is it possible that since I did not use it most of the winter, maybe the water froze or something? I don't understand how the quad can turn over like normal but not start, but as soon as I put the charger on there it turns over once and fires right up. Also once the quad is warmed up it will start up after that just fine, but if it sits for a day or so I have to hook up the charger. Should I just change the battery or is it possible that the coil or something else is bad. I really don't have 55 bucks to buy a battery if thats not the problem.

[Pappy]

its very possible the battery has sulfated.....and that would allow the battery to start the engine once it has warmed up but not start it when the engine is cold (i.e. it starts when the charger is connected)

sulfation tears these small batteries up and in as little as 60 days the battery can be junk.

there is no water/acid in your battery if it is the stock unit. they are AGM/Gell units.

[HCR250X]

If the battery is sulfated would it allow the the quad to turn the starter over fine, but cause a weak spark? I am really lost here because it turns over like its fully charged but wont start untill the charger is on it, which makes no sense to me?

[Pappy]

yes its possible for a battery to spin the egine yet not provide enough power to generate whats needed for the coil to provide adequete spark.

the only sure fire way to figure out if its the battery is to have it tested.

if you have a multimeter you can do it while its in the bike

[HCR250X]

Yes we have a multimeter in school, I will have to borrow it tomorrow and get back to you, to let you know how it went. Thanks for all the help pappy!

[HCR250X]

I got the multimeter and checked the battery today, it said I have 12.87 volts. So I'm guessing thats not the problem. Any one have any other ideas? I still can not start it cold without the charger hooked up, and it beginning to be a pain in the @$$!

[Aceman]

Get your quad started and put a multimeter on your battery. Make sure the stator is charging it properly. It should register around 13.5-14.5 volts if everything is working correctly.

[HCR250X]

14.61 volts at idle, so that cant be the problem. Could the CDI or something along that line cause this?

[wheeltrax]

Have you replaced your spark plug, sometimes a weak plug can make starting a chore. Sometimes its as simple as a new plug. It could help.