Yes you are allowed / restricted to four motors per page 18 in the rules. 

On Sunday, October 19, 2014, Ralph Grove <[log in to unmask]> wrote:
Hi
Is there a restriction on number of motors allowed for FLL robot mission. EV3 has 4 ports but get only 3 motors with the kit. Wondering if the fourth motor is allowed for robot game in FLL 2014 season.

Thanks
Dilip Coach - Kingdom Krashers

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