At the
1991 IFMAR 1:10 Electric Off-Road World Championships, Team Associated had built a series of new RC10s for the 2WD class weeks before and had little time to prepare. After a poor practice performance with two practice days left, Lett split the team into groups of three and four; one group focused on front-end development, a second on rear-end development and a third on tires. The arrangement succeeded, and
Masami Hirosaka won his second IFMAR 2WD world championship. In the 4WD class Lett qualified his
Yokomo YZ-10 in sixth place, despite losing his fastest qualifying time for failing to
marshal a round after his. He fought out the first leg of the A-Main (the finals that claims the championship title) with Hirosaka, who held the lead in the five-minute round until he made an error which allowed Lett to win. In the second leg, as Hirosaka made mistakes which left him in fourth place and reduced his chances of contending for the championship, Lett tried to fend off Jack Johnson's
Kyosho Lazer ZX-R. He rolled his car on the seventh lap, enabling Johnson to pass, and finished second. In the final leg, Lett needed to finish third or better to secure the title. After an error by Johnson, he and Hirosaka were the only remaining contenders. With the lowest points deducted from each driver's final score, they were tied; their lowest scores were used to break the tie. Hirosaka's fifth-place finish in the second leg was lower than Lett's second, and Lett was declared champion. == Record attempt ==