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Have a Razor 500 , upgrading motor, 48v not an option

I have a razor mx500 and the motor is burnt out, i have 3 12v 22amp hour batteries in it so no room to go 48 v, was wondering what to do for a replacement motor,

Thinking possibly a 500w 24v and a smaller sprocket, also noticed you have a 600v 24v would that fit into the razor with out any modifications..

If not what part number for motor do you recommend and what sprocket, this is for a 55lb kid going threw lots of tall grass in fields and up slight grades.. 

or would we go to a 750w motor with a higher amp controller if so what part numbers would those be..


This thread is aimed at TNC Scooters who recommended I post the question here for their engineers to answer the question 

If you install a 24 Volt motor along with the existing 36 Volt battery pack and controller that would overvolt the motor and cause it to run at a higher RPM and also to consume more power than it is rated for, so we recommend to install a more powerful 36 Volt 1000 Watt (SPD-361000B) controller along with the 24 Volt 500 Watt motor (MOT-24500X2500). Since the overvolted 24 Volt motor would be spinning at faster RPM than the MX500's original motor a smaller motor sprocket would help to lower the gear ratio however most 24 Volt 500 Watt motor come with an 11 tooth sprocket which is the the smallest size available for them.

If you order an upgrade motor from TNC or ESP you will need to request that they send you one with inset cover bolts instead of with bolts that are on the outside of the covers. This way the motor will fit the MX500 frame without modification.

Our 24 Volt 600 Watt motor would not fit the MX500 or MX650 without modifications.

Installing a 24 Volt motor with a 36 Volt battery pack would be an overvolt modification which can be tough on parts so there is no guarantee how long the motor or controller would last if this was done. It would be safer to install a larger 36 Volt 750 Watt motor (MOT-36750) and controller (SPD-36800B) in regards to reliability of the parts. However the top speed and torque that an overvolted 24 Volt 500 Watt motor has could not be obtained with a 36 Volt 750 Watt motor, so its a choice between reliability and speed/power when deciding which of these part to use.

Please keep in mind that the controller part numbers shown above are not plug-and-play for the MX500 dirt bike and would require custom installation including cutting and splicing wires or installing new connectors and rewiring.

The easiest thing to do would be to replace the burned out motor with another 36 Volt 500 or 650 Watt motor, because then the MX500's original speed controller and wiring could be used.

Please let us know if you have any questions.

would the 36v 650watt motor give the bike some more low down power? or do you need to change controllers?  Also which sprocket would you recommend for that .?

I have not installed a 650 Watt motor on an MX500 dirt bike before so I do not know where in the RPM band the extra 150 Watts of power would be.

The MX500 controller is the same one that the MX650 uses so it does not have to be changed when upgrading from a 500 to 650 Watt motor.

If you are looking for extra toque to ride through tall grass and climb hills then installing a larger rear wheel sprocket would be the best way to get it. We sell an 89 tooth sprocket that fits the MX500 dirt bike which will give it more torque. It is our item # SPR-2589. I checked and this sprocket is currently on backorder though so we do not have any in stock right now. We could send you an email when it is back in stock if you would like?

Please let us know if you have any questions.

Can you email me or reply in here when the 89 Tooth is available?  also any estimated timeframe on when you will have it back in?

You got it, I entered your email for a back in stock notification email when SPR-2589 is back in stock.

Estimated back in stock time is a pretty long time since we import these. They should be back in stock in around 3-6 months. We will let you know as soon as they arrive.

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