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Need help troubleshooting mx650

1905 Views 6 Replies 4 Participants Last post by  tiffjcummings
My kids mx650 stopped running after 2 years. Hit the throttle and it barely moves. With the rear wheel off the ground the motor spins at pretty low speed.

-Batteries show 39.7 volts, 13.x volts each
-speed controller output at full throttle with motor plugged in shows ~10v
-speed controller output at full throttle with motor unplugged is 30+ volts

Im thinking there is an issue with the motor. Is the any way to test the motor?

Any other suggestions before I start throwing mony at ths thing?

All help s appreciated.

Thanks
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Wit them test results its a no-brainer,,the motor is shot...to make sure connect the battery direct to the motor to see if it spins full out...if so then you have a weird controller issue...If not replace the motor or the brushes
I will try that. However, im starting to think it is the batteries. I put the multimeter on the batts and it read 39, gave it full throttle and the voltage dropped immediately to 29v. Rechecked with no throttle and voltage was down to 30v. I only ran it for 15-20 seconds with the back tire off the ground.
I will try that. However, im starting to think it is the batteries. I put the multimeter on the batts and it read 39, gave it full throttle and the voltage dropped immediately to 29v. Rechecked with no throttle and voltage was down to 30v. I only ran it for 15-20 seconds with the back tire off the ground.
Could be but in my experience a motor with bad brushes,,commutator or armature will hot soak batteries pretty quick and show a decline similar to dying batteries but with the couple years you have on it I wouldnt doubt if you may have to replace both..........................
I would load test the batteries for amps also if you can, I would charge mine on my 24v razor rocket and they showed 12+ volts but would barely turn the rear wheel.
Turns out it needed new batteries.
Im new and cant do a new thread yet but I really need some help. I just bought an electric XRF 500 minimoto dirt bike. Wehn i bought it the guys said it was running but when he showed it to us it didnt do anything, He said the guy the day before must have left the key on and drained the battery, so we bought it anyway. So we get it home charge it a full 12 hours and nothing? So I start researching it and read that it may be the voltage regulator/motor controller, so I bought a new one and had to rewire it a lil to make it work but still I am getting nothing. I tightened the brake wire so it cant be that, the back tire is flat does that have anything to do with it? It makes no sounds at all???? Yes I am a female lol so I really need some help its for my 7 year old son :)!
Also sicne we couldnt get that one running before Xmas we bought a raxor a smaller one, electric also and it ran, I rode it around the yard a couple times and everything. Well I charged it all night before xmas and went back into my utility room to get it and smelled a kinda burn smell so i immediately unplugged it, i figured the new charger we just bought with it was just breaking itself in. Anywho my son got on it xmas day and it is sluggish he literally has to walk the thign around the yard??? So im thinkin maybe one of the 12 volt batterys went bad???
the first bike is a 36 volt and this pocket bike is a 24 volt??
someone please help lol.. sorry for any mispellings I am rushin trying to get ready for work. have a nice day and thank you for any help :)!!!
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