M.L. Toys
M.L. Toys
HobbyMasters M.L. Toys
Electronic Scooter Controllers have become a popular addition to our vehicles. Ask specific questions about ESCs here!

***WARNING*** this section is for ADVANCED MODDERS. if you try anything in this section you NEED to expect minor issues with the build up to and including complete FAILURE of EVERYTHING in your freshly built BPRO.

Have fun ;-) :-)
By trek920
OK, so I have read a byunch of threads abtou this.

I'm having the following issue:

Switches will not light up (dont really care, but woudl be nice)
A high pitched wine comes from a very small speaker hidden near the circut breaker. its noise is intermittent, sometimes strong.

I get nothing when the throttle is pushed. Ive taken it out, and cleaned off the magnet best I could. its not very pretty, but it moves.
I get nothing in rev or fwd. brakes work though.

I have no clue where to go from here. the SC seems to be a solid block of black and un serviceable (or so i think)

Any ideas on where to go next? I am missing the emergency pull bat that kills the circuit in the back, and since I don't have one, i shoved a socket ext in there. Do not know if this would work, and im thinking of just wiring together those two leads.

Getting around 37-39 fully charged.
Last edited by trek920 on Sun Mar 17, 2013 12:04 pm, edited 1 time in total.
User avatar
By Racer X
A high pitch sound is suppose to be for the battery being low,.... it is also typically the kiss of death for your controller. What you can do is hook the battery directly to the motor. If it spins then most likely your problem is your controller. There is no directly replacement, but you can get a model that will drive the kart from TNC. You just need to trace all the wires back and make a wiring harness to jump your old connections to the new harness.

Here is the rub,..... there were different model controllers used in the kart, so there is no definitive answer in regards to what wires go where. There are about three types that have been successfully traced, I have done one myself with no problems, but I fried another the second I turned the power on (two separate karts). There are several threads that should get you started. If you have a specific question feel free to ask.

Racer X
Last edited by Racer X on Mon Mar 04, 2013 11:26 pm, edited 1 time in total.
By trek920
this one? ... uct_id=182" onclick=";return false;

Im assuming it needs to be 40 amps.
By trek920
didnt come with that part. I bypassed it
User avatar
By hootienchyna
well like stated earlier either your batteries are not at at least 36v or your controller is bad, thats the 2 things that it would be.
and its about a 70 dollar controller
Last edited by hootienchyna on Sat Mar 02, 2013 8:17 am, edited 1 time in total.
By trek920
the one on TNC was 30 bucks. my batteries are over 36, and they are new. checked the hall throttle, its good too. So I agree.

when it comes in, i'll post up more progress. There is about 4 connectors I have no use for as there are no lights, etc on this thing.

Voltage to controller
Throttle to controller
brake to controller
Switch/lock to controller
controller to motor
By trek920
yes but that's only 30 amps. I was thinking of wiring in a reverse between the speed controller and the motor. Wanted a 40 amp controller.

Im thinking of tearing this thing down and washing it, and getting all the crap out of the places, and re-oiling the chain, etc. the motor spins like a champ, so I cant wait.

but the plastic parts seem soooo brittle. i dont want to re-enforce with fiberglass, so might cast and remold the parts.
User avatar
By Racer X
If you cast and remold parts I would be very interested in seeing how it turns out (there is quite a market for replacement parts if you want to hang out a shingle -- I can point you to a site where you could get some activity immediately.

Racer X
By trek920
I have in the past, but not for gokarts or anything. expensive hobby. vacforming is much easier
By trek920
got new controller. the power switch in my steering is bad. fired right up though.

Will Have to replace body panels though. cant wait to drive it! needs new front tubes however.
User avatar
By Racer X
How much would you be willing to pay for two rear tires (you can pull the tube out and used the tire as well (excellent thread still remaining)?

Racer X

(if you are interested PM me because I do not check the form as much these days because things are slow until the spring)
By trek920
we have more than 10 gokart shops here in town, can get tubes pretty easily. im thinking 6 bucks each.
By trek920
Had this thing out yesterday. only half filled front tires as our tire inflator doesnt seem to work very well.

Lasted I'd say abotu 25 minutes or so on a full charge.

States are average speed 8mph, top speed 17mph.

I would figure itll be faster if I try the speedo at full charge instead of 15 minutes later. Looking for a accelerometer that registers G-Forces... any suggestions?
By TangoU
I have a similar issue it sounds as the OP. I bought two of these karts last summer and they worked fine. They sat this winter but now that summer is back my son wants to drive them. Unfortunately, both emit a high-pitched whine when the throttle is hit. They will run for 5 - 10 seconds and then the whine will start and the kart will stop. Both karts are exhibiting the same behavior.

I have tested the chargers on my multi-meter and they are putting out about 40v. The batteries read out about 39v on the same multi-meter Is the voltage somehow now too high? Is it that both controllers have gone out at the same time? How do I test further to find the source of the problem?

thanks for any help.

User avatar
By DennisDaMenace
If you did not charge your batteries while they were stored during the winter then your batteries have gone bad. This is confirmed by the high pitched sound. Measure the battery voltage connected to the controller and hit the throttle. If the battery voltage drops to below 30V then you'll need to replace the batteries.
By TangoU
Sorry for the long delay. Had a computer crash and finally got that fixed...

I purchased a new 36v battery, installed it, charged it up over night, and tried it out with great expectation the next morning. Same high pitched whine...

So if it's not the battery, I guess somehow the controllers on both karts crapped out at the same time?

Thanks for any help. Difficult to find much info on these karts. You'd think if the kart has this speaker thing it'd be documented somewhere, but unfortunately that's not the case.

By bigsaff
I am in a similar situation. I bought 2 of these carts for $60. I have put together a battery pack for testing and I can get one of them to work...for a few seconds. I get the "squeal" when the on/off switch makes good contact, but only for a second. I have read to check out the accelorator pedal as well. I just haven't gotten that far. But when I make a good connection, the cart goes (very slowly) for about 3-5 seconds, then stops. Any ideas on where I should go with it next?
By bigsaff
Seems as though this thread may be dead. Nonetheless, I will update my adventures in case someone else can benefit.

I did a couple of things to get things rolling:
1. Bought a new set of batteries. Wired them up and tested. I was getting intermittent success.
2. Tested both controllers with the new batteries. It appears one is good, the other is bad.
3. Cleaned out the accelerator pedal/switch with a wire brush and checked the connections. Much better afterwards!
4. Replaced the On/Off switch in the steering wheel. This is where my intermittent problem was coming from.
5. Painted, oiled, and lubed everything.
6. Created a box to cover the battery.
7.Now to give it to my son!

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