I have a 150cc china BMX quad and it used to turn over and start... but the battery would go dead, we would charge it for awhile and then it would turn over and start... then all of a sudden the battery won't take a charge anymore so I thought.. the wheeler is currently acting like it has a very dead battery so I went a got a new battery put it in and nothing not even a click... if i jump the solenoid it will turn over but has a very weak spark, and won't start even with ethither, i replaced the voltage reg. CDI box and the safety switch for the shifter, I do not get any power to the starter button using a test light, I do get headlights and taillights, i get no power to the solenoid at the two light gauge wires that come from the voltage reg. is there anything else that i should be checking or replacing... oh one more thing... i believe that i checked all of the connections for every wire for everything thing possible.. could it be the left brake safety switch?

 

Is this a GY6 150cc engine?

Did you charge the battery after putting the new one in? When you add acid to the new battery it only comes up partially charged. You need to charge it with a motorcycle battery charger for a few hours to top it off.

GY6 quads use a brake safety switch to keep the quad from starting unless the brake is depressed. That way it won't start in gear and take off unexpectedly. Usually the starter solenoid is fed power from the brake light wires. The other side of the solenoid is grounded through the start button.

So do your brake lights light up when you turn on the ignition and step on the brake (or pull the brake handles)?

When you jumped the solenoid did the quad starter turn at normal speed, or did it run slower than normal?

 

thanks for the reply... i hope i can provide you with the answers you need to help me get this thing started/turning over, let me know if you need anything else...

ENGINE: i am not sure if its a GY6 engine from pictures on the internet, it appears to be, but i am not 100% sure... BATTERY: yes I followed the recommend procedure for charging the battery the first time and even charging the battery out of the ATV first, the battery seems to allow very bright headlight and taillight.. BRAKE LIGHT: I have one bright headlight, but no the brake light do not get brighter when i squeeze the handle bar brake (it does not have a foot pedal), but does light up when i turn the headlights on. SOLENOID: when i "jump solenoid" the the starter seemed to turn at a slower speed than normal, however the battery seems to be fully charged

thanks again...

 

The lack of a brake light may be why your starter button is not working.

But first lets find out why your starter is spinning slow when you jump the solenoid:

Turn on the ignition switch and turn on the headlights. Set the brake and make sure you are in neutral (just in case the quad starts up). Jump the solenoid. While the starter is turning (slowly), do the headlights stay bright? Dim a little? Dim a lot? Go out?

Jump your quad battery using jumper cables to your car battery. When you do this make sure you get the polarity right. Short the solenoid posts again. Does the starter turn normal speed? Does the quad start?

Can you post a picture of your engine? Is is fully automatic with a CVT (continuously variable transmission), or do you shift gears with a clutch?

 

i think that it is a GY6, i tried to upload a photo but it failed... per your question... "does the lights dim" they do a little but not all of the way. i wasn't able to jump it using a auto yet... i begining to think its the safety switch at the hand brake... is there a way to by pass it to see if indeed that's it? i removed the wires.. won;t start.... i ran a wire from from each wire won;t start... does it need to be grounded to the handle bars.. right now i have it off the handle bars but still hooked up. still no results

 

Any brake safety interlock will keep the starter from turning at all. When you turn on the ignition switch and short the solenoid you are already bypassing the safety interlocks. That's why I said to set the brake and make sure you are in neutral first. If the quad should somehow start up you want to make sure your quad is going to stay put.

But you say the starter is turning slow when you bypass the solenoid, and it won't start. Also you say the starter button won't engage the starter. These are looking like two separate problems. If it were me I'd concentrate on getting the starter to turn normal speed by shorting the solenoid and getting the quad to start, then concentrate on why the starter button doesn't work. I'd get a pair of jumper cables, jump it to my car, and short the solenoid. Does the quad starter turn at normal speed?

 

But you say the starter is turning slow when you bypass the solenoid, and it won't start. Also you say the starter button won't engage the starter. These are looking like two separate problems. If it were me I'd concentrate on getting the starter to turn normal speed by shorting the solenoid and getting the quad to start, then concentrate on why the starter button doesn't work.


I'd get a pair of jumper cables, jump it to my car, and short the solenoid. Does the quad starter turn at normal speed? - I did this...see below!

when i used a set of jumper cables from my jeep to the ATV neg to the frame and pos to to the pos. post directly on the solenoid itself....it would turn over very quickly... but still wouldn't fire......might I also add that the brake light seems to be awful bright and does not change if i put the brake on or not... and i did put on a new brake safety switch.. didn't change anything.

 

You have multiple problems. All of them are solvable, but to keep from getting overwhelmed you need to divide them into individual problems and solve them one at a time. Divide and conquer. You've already zeroed in on one: Your starter turns normal speed when you jump to your jeep. What that says is that you bypassed your battery and negative battery lead to the frame together with solid 12 volts and the starter turns. This is progress. I would repeat the test (because it is easy to do) only this time connect both jumper cables (plus and minus) from the jeep battery to the quad battery (not the quad frame). If it still cranks fast then you have eliminated bad connections from the battery minus terminal to the quad frame. This zeroes in on the first problem even more.

I expect you will find that the quad battery isn't up to snuff - but do the tests because bad grounds happen and can be frustrating if overlooked. Do you have a charger? Batteries that are left sitting discharged are destroyed quickly.

Next problem: Are your getting spark? Have you checked for this? Do you know how to check for this?

 

I forgot.

As far as the brake light being "awful bright": When your quad isn't starting up the only source of significant electrical power is your battery. Batteries put out roughly 12 volts maximum. Your brake light is designed to run on 12 volts. The worst that could happen is that the entire 12 volts is applied across the brake light. This is not a problem. This is normal. I suspect you have just gotten used to an abnormal condition.


You changed the brake switch and now the brake light stays on all the time. Unplug the brake switch. Does the light go off? If yes then your brake switch is bad or just misadjusted.

 

i am getting a very weak spark... mostly a brown spark, not the bright blue or white that typically happens.. if it was turning over and i had no spark... at least i would have a better understand of whats happening, i even squirted a little starting fuild but still not turning over.... however to answer your questions... when i hooked up the jumper cables to the atv battery and crossed the solenoid and it turned at normal speed, so yes the battery might be a little undercharged but even so.... one would think that it would at least start when jumped with the car battery... something is preventing it from turning over along with a good spark... and then you keep talking about a brake switch.. the only one that i see it the one on the left side of the handle bars and thats is the one i replaced... it has two wires leading to it... as for the right brake.. thats for the front tires and is a cable.. anything else you would like for me to try?

thank you for your help so far!!