FIM has adjusted the balancing technical regulations for the 2018 Supersport 300 World Championship following the results of the first round of the season April 13-15 at Motorland Aragon and ahead of the races this weekend at TT Circuit Assen.

At Motorland Aragon, riders on the new 2018 Kawasaki Ninja 400s and KTM’s RC 390 R homologation specials dominated riders on the Yamaha YZF-R3, like the one Marc Garcia used to win the 2017 FIM Supersport 300 World Championship.

Riding a Kawasaki Ninja 400, Mika Perez took pole position at Motorland Aragon with a lap time of 2:07.938 (and a trap speed of 126.88 mph), which was nearly five seconds faster than the 2017 pole position time of 2:12.712 Scott Deroue turned on a Kawasaki Ninja 300! The highest-qualifying Yamaha rider at Motorland Aragon was Galang Hendra Pratama, who was 11^th with a time of 2:10.208 (and a trap speed of 121.60 mph).

The race at Motorland Aragon was won by Koen Meuffels on a KTM RC 390 R, while the highest-finishing Yamaha rider was Daniel Valle in 13^th, 15.014 seconds behind Meuffels at the checkered flag.

FIM responded quickly and on April 19 issued a technical bulletin to competitors that adjusted the balancing regulations.

The following changes were announced:

The Kawasaki Ninja 400 had a maximum rev limit of 12,000 rpm, and that has now been reduced to 10,850 rpm.

The KTM RC 390 and RC 390 R had a maximum rev limit of 11,000 rpm, and that has now been reduced to 10,450 rpm.

The Yamaha YZF-R3 had a maximum rev limit of 12,850 rpm, and that has now been raised to 13,100 rpm.

The Honda CBR500R had a maximum rev limit of 9,500 rpm, and that has now been raised to 10,200 rpm. Also, the Honda CBR500R had a minimum weight limit of 156 kg (343 pounds), and that has been lowered to 153 kg (337 pounds).

In addition, the Yamahas can now have modifications made to the airbox, including altering the cover of the air filter, shortening the air funnels, and removing the rubber intake tube. And the Hondas can also have modifications to the airbox, including opening up the intake snorkel and air filter cover and shortening the air funnels.

MotoAmerica is monitoring the affect that these changes have on the results in the Supersport 300 qualifying and races this weekend at Assen before they make any changes to the regulations in the Liqui Moly Junior Cup, according to MotoAmerica Technical Director James Morse.

The FIM Supersport 300 World Championship race at Assen happens on Sunday.

Stay tuned.