will 2008 yfz450 run with battery disconnected

[go2glamis]

i have gone through two brand new battery in two rides it starts and runs great then with no warning it just dies. the battery wont charge after. it shorts out and I have to replace it. my question is should the bike run with the battery disconnected. I have a new battery in now and changed the rectifier and when I take the cable loose it dies. is this normal

[Frank Angerano]

Hey @go2glamis welcome to Quadcrazy. I would check your stator coil.   It could be over charging the system. Or not charging at all.   You need to see what voltage you have coming from the stator as well as do an ohms test on it.   The engine should run with the battery disconnected, the lights and accessories would not work properly and may shut the engine down if you were to turn them on due to a heavy draw but the engine should run with the battery disconnected. 

 

[go2glamis]

Thank you very much. Do you know where I would be able the find the procedure and specs to test that? 

[Frank Angerano]

Here a few pages from the manual. It’s not the same year but should be close enough if not the same.  

I would also start the bike up and put a tester on the battery and see how much voltage your getting at the battery.   As your checking rev the engine a little and see if it changes. Are you handy with an electrical tester ? 

 

 

[go2glamis]

Yes I actually tested it already It was staying at 12 to 12.5 then I changed the rectifier and now getting about 14 which is good but it stll dies when the the battery is disconnected so maybe the bike is running off the battery and not the stator

[Frank Angerano]

That Could be possable. Test the stator and see what you get and go from there.  Have you checked all the connections as well as your grounding from the battery to the frame? Was the regulator/rectifier an oem part or aftermarket? 

[go2glamis]

Everything on it is stock except the pipe and I put an oem rectifier back on. Not a big fan of aftermarket stuff. But I will also check all my conections

[Frank Angerano]

Ohm out tye stator and see if it’s in range 

[go2glamis]

Ok thanks for all the help I well add to this when I get get all your suggestions tried out and it's fixed

[Frank Angerano]

Definitely check all the connections and think about anything that could have happened like a smashed wire somehow, have you tried to jump start the bike with a car by chance ? That can cause problems internally with the rectifier and cdi as well as he stator. Over amperage kills that stuff easy.   

[go2glamis]

Not a car but a charging system and only after the first time I had this issue with a brand new battery that failed

Ok I checked stator and it's only reading 0.150 so will replace and give an update when I get it installed 

[Frank Angerano]

Ok so it’s below range. Could be that’s your problem.  Where are you going to get the parts ?

[go2glamis]

Should have the part end of week and installed in a week or two

[Frank Angerano]

Ok good luck.  Keep us posted.  

Gaskets don’t forget gaskets.  

[JacobSlabach]

wont it hurt the electrical on a bike to run it without the battery hooked up?  Thats what I've heard...

[Frank Angerano]

No.   

[JacobSlabach]

ok.  rumors are wrong then🤣

[go2glamis]

Just an update

I ordered an aftermarket stater cause it was cheaper (stupid me) I don't have good luck with aftermarket parts and it did not work so returning it and getting the stock one 

[Frank Angerano]

What brand did you get just curios. Reason I’m asking is I’ve ised one aftermarket brand and it worked great.  

[go2glamis]

QA brand from rocky Mountain they had the Ricky stator but I don't need the 100 watt and it was more then stock

[Frank Angerano]

Caltrec. So far two years into it on my bear tracker and I beat the crap out of it. No problems. I’ve used them on other bikes with no problems. 

[go2glamis]

OK new stator is in i can disconnect battery now and the engine still runs so definitely the stator was bad. now i was hoping that would solve my other problems to but didn't.  i don't ride at night much but my headlights don't work and i can only start the bike with the clutch pulled in (wasn't this way new) the tail and brake light work. is there a fuse or relay for these? i changed the neutral sensor before but didn't help 

i can rebuild or troubleshoot almost any engine but am horrible at electrical     

[Frank Angerano]

As far as the starting the bike with the clutch pulled in thats normal. Most likely solved that with the neutral sensor.  You may have never knew it but that’s how it works.   As far as head lights that can be traced back to the power source.  Either a bad connection or fuse.  Pull the connections at the lights and test for voltage. There should be three wires on your headlight.  One is a ground two others are high and low beam.  Start there and check for power with the head light switch on obviously.