Kymco MXU Mongoose 250 300 Starter Motor 2003–2014 | 31210-LBA7-900

Product Overview

Restore reliable electric starting performance to your Kymco ATV with this 12V 9-tooth starter motor.

Designed to replace Kymco OEM 31210-LBA7-900 and 31210-LBA7-90B, this starter motor helps deliver dependable cranking power for compatible Kymco MXU, Mongoose, Maxxer, and KXR 250 / 300 ATV models.

It is a practical replacement for common starter-related issues such as slow cranking, no-start problems, intermittent starter engagement, worn internal brushes, or a failed original starter motor.

Product Compatibility

Brand	Model	Sub-Model / Notes	Year Range	OEM Reference
Kymco	Mongoose 250	ATV model	2003–2009	31210-LBA7-900, 31210-LBA7-90B
Kymco	Mongoose 300	ATV model	2005–2014	31210-LBA7-900, 31210-LBA7-90B
Kymco	MXU 250	ATV model	2004–2009	31210-LBA7-900, 31210-LBA7-90B
Kymco	MXU 300	ATV model	2005–2009	31210-LBA7-900, 31210-LBA7-90B
Kymco	Maxxer 250	ATV model	2004–2009	31210-LBA7-900, 31210-LBA7-90B
Kymco	Maxxer 300	ATV model	2005–2009	31210-LBA7-900, 31210-LBA7-90B
Kymco	KXR 250	Select ATV applications	2006–2015	31210-LBA7-900, 31210-LBA7-90B

OEM Cross Reference

OEM / Interchange Number	Brand / Reference	Notes
31210-LBA7-900	Kymco	Main starter motor replacement number
31210-LBA7-90B	Kymco	Interchange / related starter motor number
31210LBA7900	Kymco format	Same number without dashes
31210LBA790B	Kymco format	Same number without dashes
1781120	Aftermarket reference	Use as secondary interchange number only
3304-274	Aftermarket / cross reference	Commonly listed interchange number
S31200-RB1-000	Aftermarket / cross reference	Commonly listed interchange number

Specifications

Specification	Details
Product Type	Electric Starter Motor
Voltage	12V
Gear Teeth	9 Teeth
Rotation	Clockwise / CW
Replacement OEM Numbers	31210-LBA7-900, 31210-LBA7-90B
Installation Hole Distance	39 mm
Overall Length	180 mm
Application	Kymco 250cc / 300cc ATV starting system
Installation	Direct replacement when dimensions and OEM number match

Key Features

• Replaces Kymco starter motor numbers 31210-LBA7-900 and 31210-LBA7-90B
• 12V 9-tooth starter motor with clockwise rotation
• Designed for compatible Kymco MXU, Mongoose, Maxxer, and KXR 250 / 300 ATV models
• Helps restore reliable cranking and electric starting performance
• Practical replacement for a weak, worn, or failed original starter motor
• Built for ATV starting-system repair and everyday riding use