This should be an easy one...

I have one of the Sunl 110 models.. it was running great a couple days ago. Tonight it stalled out shortly after starting. I cranked it and it run about 30 seconds, then stalled. I put a jumper battery on it and it ran as long as it was connected. I removed the jumper and it stalled shortly after. Jumper on runs like a top, jumper off and it soon dies.

It obviously is not producing enough juice to run the motor, let alone charge the battery, but I don't know what part should I be looking at? I figured the stator (although I'm not sure how to get to it or test it) but are there any other parts I need to think about.

 

This doesn't sound so easy to me because there are a lot of things that don't make sense:

It stalled, but you were able to crank it. That says your battery is fine. Then it ran for 30 seconds and died. Then it wouldn't run unless another battery was jumped across.

Did you need to jump in a new battery to crank the engine and start it back up? Your post is not clear on this. If not, than this is further evidence that that battery is OK. If so, it doesn't make sense: How could the battery that just started the quad go dead in 30 seconds while doing nothing but running the engine?

Whenever things don't make sense then more information is needed.

Some things I'd like to know:

1) If you start up the quad (with jumper cables if necessary) and you then pop out the main fuse, does the quad immediatley die?

2) When the quad is running, turn on the headlights. Disconnect the jumper cables. When the quad dies, do the headlights go out? If so, do they go out suddenly, or do they fade out out slowly before the engine quits?

3) Is there any possibility that the squeezing of the jumper cables when you connect them is fixing an intermittent (bad) connection at the battery terminals?

One assumption I'm making is that you have a 12 VDC powered CDI, as compared to the more traditional AC powered CDI that runs off the stator. I'm making this assumption based on the fact that quads with traditional CDI's run just fine (once they are started) with the battery disconnected and removed.

Do you have an alarm system on this quad? If so, disconnect it and see if the symptoms are the same.

 

I've only got a minute or two so I'll add what I know, and add more later..

I know I could jumpstart this quad and run it with a bad battery in the past. I know that the current battery holds a charge, and had some charge on it last night, but gradually died. I know the headlight was working, and would get brighter when the engine was rev'd (but we only ran it with the headlight about 50 yards.

It was cold out, so it takes several tries to start. I originally started it with the onboard battery, but it stalled out, and the starter was beginning to drag, so I hooked up a jumper battery for more kick. The starter motor turned over much faster, and she cranked. When it's cold, you have to nurse it and adjust the choke to keep it running until it warms up.. that's normal. It stalled a couple more times and I cranked it with the jumper battery.. the only thing unusual was that a couple times, I though it stalled just as I removed the jumper battery, and that wasn't normal.

It then seemed to run fine, so I remove the jumper battery and we took off on a ride. At first the headlight was on, and bright, but I told my daughter to shut it off and save the battery. About 500 yards into the ride it died. I cranked it using the onboard battery.. it ran 30 yards and died. I cranked it again (onboard).. it ran 20 yards and died.. The onboard battery at that point barely turned the starter over.. so I used the jumper battery again.. when I pulled the jumper battery, it ran about 2 feet and died..

At that point, my feeling was that it was running the ignition off the battery and the battery wasn't giving it enough juice to run for any length of time... it will keep running as long as I have the jumper battery connected. I haven't charged the onboard battery yet, but I believe if I do.. it will run till the battery is drained.

1.) I'll have to try the fuse after work
2.)Same as above
3.) I don't think so

Thanks for your help... I'll follow you instructions in the morning (I have to work late tonight)

 

Ok, tried a few things as suggested...

1.) Internal battery had some charge on it this morning.. but it is 40 degrees. I tried starting it a few times with the internal battery, but didn't want to kill it, so I used the jumper battery and it started after 10 or so attempts. I let it warm up a bit, and removed the jumper battery. Seemed to be running fine. I removed the visible fuse that seems to be the main fuse, and the quad kept running.

2.) At this point, I had my daughter ride it around and after about 5 minutes it died. It started once or twice off the internal battery, but died after 10 or 15 seconds. Then the internal battery went flat. I then started it with the jumper battery and it cranked right up, and ran fine. I removed the jumper battery and it ran about a minute. I watched the headlight, the motor finally started to stumble and stall... the headlight faded with the slowing of the motor and cut off with the motor. I hooked the jumper battery back up without starting, and the headlight did not come back on. I cranked the motor with the jumper, and the headlight came on with the motor. I removed the jumper battery and after 30 seconds or so, the motor stopped. I tried restarting with the internal battery and the battery is flat.

3.) I wiggled the battery connections with the motor running on the internal battery and saw no difference in how the motor was running.

This ATV is a camo model the says ATV-109B on the side. The manual I got with it says its for the 110ST/90ST/70ST/50ST and the picture on the cover matches the ATV. I don't know who the manufacturer is, but it looks like some of the models listed under the SUNL websites. The part. number listed for teh stator in the manual is '50Z 31200' if that helps identify anything.

I could be mistaken, but I could have sworn I had it running with a dead battery before (I'd just jump it with the booster battery and tell her not to stall it if she didn't want to push), as the original battery was junk. I replaced it with a wally-world battery a few months ago... and this is the first time I've had any trouble out of it.

I'm probably going to take the body off and go over all the connections next... just wanted to see if anyone had some advice to focus my search. I don't know if its running until it heats up, or running till the onboard battery is flat. I guess I'll have to see how long it runs on the jumper battery.

Thanks,

 

Well, I took everything apart.. reassembled with dielectric grease, charged the battery, drained the tank and the carb float bowl, cleaned the spark plug, fresh gas... cranked her up and we went on a 20 minute ride... runs good like it always has. I don't know which of the above fixed it, and I don't care... LOL

Next time the battery gets run down (if I leave it connected it runs down in a couple days) I'll find out if it repeats the dead battery stalling trick. I usually disconnect the battery when we are done riding for the day.

Thanks,