My daughter has a 110cc Ice Bear ATV that dies constantly. I was having to boost it because the battery couldn't start it and then it would only run for a short time before dieing again. I went and bought another battery and it worked great for a short period and then it started to die again until finally the battery was too weak to start it. I decided it had to be the magneto so I pulled it out and checked it with a multi-meter. The coils have good resistance and it doesn't smell like its burnt. However, I don't know what else would keep the battery from charging. I'm thinking about going ahead and buying a new magneto. Does anyone have any ideas of what else would cause this issue?

 

Without a wiring diagram I can't say for certain, but on most small Chinese engines the sparking system is completely separate from the alternator/battery system and those little batteries won't stand turning over an engine for long before you flatten them. The bad starting and dying sound more like carb problems, but ignition coil, CDI or exciter coil could all cause a loss of spark when hot. Charge the battery, clean out the carb and if that doesn't work, buy the cheapest part to substitute first.

 

Does not take much to kill those little batteries. I have battery maintainer and i put the quick plug with the little LED to show the charge condition of the battery. Just those little led's were enough to kill the battery in a few days. Cost me a new battery to find out that a $10 part was the issue

 

The magneto provides spark and charges the battery. Is this correct? It was running fine with a new battery at first but then It started dieing and the new battery no longer had enough umph to start it.

 

Yup, you are on the right path. If it's inexpensive, just replace it.

 

The magneto provides spark and charges the battery.Is this correct? Like I wrote at the top it depends on the engine. Some have a separate exciter coil that provides the timing and power for the spark, some wire the alternator directly to the CDI and the separate trigger coil just provides a timing signal. Some have DC from the battery fed to the ECU like a car. If your system isn't the first type, easy test, get it running again and put a voltmeter between the battery terminals, if the voltage is over 13v, it is charging, so the alternator and rectifier works.

 

...or while it is running, pull the ground off the battery and if it dies, that magneto isn't charging.

That's some good info posted too.

 

So I charged the battery and got the ATV running again and found that the battery is charging, very slowly, but charging. I'm going toward the carb now like Merryman stated earlier. I can buy a new carb for like 25 bucks shipped. Is it worth it to rebuild or just buy a new one?

 

Just remove the float bowl and blow the jets and bowl out with compressed air.

 

That did the trick. Thank you. I feel as though I should have cleaned that carb when we first got the atv. It's never really wanted to start since it was new. After reinstalling the carb it fired right up not even choked, its never done that. Thanks again.