2000 Honda Trx300ex won't run unless hooked to power source- Help needed

[dominic_300ex]

My 300ex won't run unless hooked to jumper cables or to a battery charger. When I try to rev it up it gets quieter instead of louder, is the stator bad? Could a CDI cause this? Could something with the ignition cause this? The neutral light only comes on when hooked to a power source and goes off as soon as the power source is connected. After I disconnect it from a power source it'll run for a few minutes then die. It'll also pull start but pushing the gas nothing happens, the choke isn't on and the gas isn't on reserve. My friend thinks it may be a stator because after I charged the battery and went to ride it the other day the battery was drained again. Any help would be appreciated as I'm lost and don't know where to start

 

[Gwbarm]

If the neutral light is not coming on your battery is dead, but it does sound like the stator is not functioning charging the battery.

[Mech]

It sounds like a dead battery. If the battery was good and charged up, I'd expect it to run the bike for hours if there weren't too many electric starts or headlights.

You need to charge the battery with it disconnected from the bike, then turn the charger off and let it sit for an hour or four and then use a gauge to check it's voltage. It's voltage must be 12.6 or more. That checks the battery isn't self discharging. Then put it in the bike and before connecting the earth lead use the amps gauge to check for any discharge while the key's off. There shouldn't be more than about 2 milliamps. That checks the bike isn't draining the battery.

Then you connect the negative lead and start the engine and use the volt gauge on the battery to check the voltage is going up. It should go up to about 13.7 volts quite quickly and at an idle, and with a few revs and a few minutes it should get up to 14.7 volts. After a few minutes of running it should be somewhere between 13.7 and 14.7, and if you turn the headlights on it shouldn't drop below 13.7 as long as there are a few revs on. That all checks it's charging.  The last check is to turn the headlights off and hold the revs up watching the rising voltage and it mustn't go above 14.7 volts. That checks the regulator's working.

 

[kp3004x4]

Would have to agree with mech. Most newer bikes have this same ole problem either low voltage from battery or battery dead .not old bikes Wich would fire up with jumpers and run all day if you didn't kill it. With all the lights and other newfangled electronic mess on bikes nowadays it's a wonder they run at all. I miss the old days. Good luck on bike. 

[dominic_300ex]

On 4/7/2023 at 2:40 PM, Mech said:

It sounds like a dead battery. If the battery was good and charged up, I'd expect it to run the bike for hours if there weren't too many electric starts or headlights.

You need to charge the battery with it disconnected from the bike, then turn the charger off and let it sit for an hour or four and then use a gauge to check it's voltage. It's voltage must be 12.6 or more. That checks the battery isn't self discharging. Then put it in the bike and before connecting the earth lead use the amps gauge to check for any discharge while the key's off. There shouldn't be more than about 2 milliamps. That checks the bike isn't draining the battery.

Then you connect the negative lead and start the engine and use the volt gauge on the battery to check the voltage is going up. It should go up to about 13.7 volts quite quickly and at an idle, and with a few revs and a few minutes it should get up to 14.7 volts. After a few minutes of running it should be somewhere between 13.7 and 14.7, and if you turn the headlights on it shouldn't drop below 13.7 as long as there are a few revs on. That all checks it's charging.  The last check is to turn the headlights off and hold the revs up watching the rising voltage and it mustn't go above 14.7 volts. That checks the regulator's working.

 

So right now the areas to check are the regular and stator?

[dominic_300ex]

On 4/7/2023 at 2:40 PM, Mech said:

It sounds like a dead battery. If the battery was good and charged up, I'd expect it to run the bike for hours if there weren't too many electric starts or headlights.

You need to charge the battery with it disconnected from the bike, then turn the charger off and let it sit for an hour or four and then use a gauge to check it's voltage. It's voltage must be 12.6 or more. That checks the battery isn't self discharging. Then put it in the bike and before connecting the earth lead use the amps gauge to check for any discharge while the key's off. There shouldn't be more than about 2 milliamps. That checks the bike isn't draining the battery.

Then you connect the negative lead and start the engine and use the volt gauge on the battery to check the voltage is going up. It should go up to about 13.7 volts quite quickly and at an idle, and with a few revs and a few minutes it should get up to 14.7 volts. After a few minutes of running it should be somewhere between 13.7 and 14.7, and if you turn the headlights on it shouldn't drop below 13.7 as long as there are a few revs on. That all checks it's charging.  The last check is to turn the headlights off and hold the revs up watching the rising voltage and it mustn't go above 14.7 volts. That checks the regulator's working.

 

So right now the areas to check are the regular and stator?

[Mech]

Have you tested the battery yet ?

[Gwbarm]

I would just put a new battery in it first, battery can fool you ,seems to charge up and bam your down again, battery are something I don't mess around with if its 3 yrs old I would replace it. I have had them not even last a year.

[kp3004x4]

Yes sir batteries are finicky with vibration and temperature and charge state ,I've seen some bikes not run at all if the battery was not fully charged.