Founded June 1, 2026 - Castle Rock, Co
Derek “Diesel” Kirtley #37
is a 15-year-old off-road racer from Castle Rock, Colorado competing for SK Powersports Racing aboard his SK Powersports Kawasaki KX250XC. Nicknamed “Diesel” since he was a baby for his strong, no-nonsense personality, Derek brings that same determination to the track. Known for his smooth, consistent riding style and relentless work ethic, he is dedicated to improving every time he lines up at the gate while pursuing his dream of a professional racing career.
Mike “Honcho” Kirtley
is the owner of SK Powersports and Crew Chief of SK Powersports Racing. A factory Kawasaki Trained and certified technician, Mike handles motorcycle maintenance, race preparation, suspension setup, and trackside support for the team. His focus is simple: keep the bikes reliable, competitive, and ready to perform on race day.
SK Powersports Racing Kawasaki KX250XC
The official race machine of Derek “Diesel” Kirtley.
Built and maintained by SK Powersports, the KX250XC is prepared for hare scrambles, sprint enduros, and motocross competition. Every race, every training session, and every upgrade is part of an ongoing commitment to performance and rider development.
RACE RESULTS & UP COMING EVENTS
Aztec Spring Classic
Date: March 21, 2026
Class: Mini 4
Finish: 10th / 20
A challenging race to start the season. The day provided valuable race experience and set the foundation for the season ahead. Diesel finished 10th overall and completed the 45 minute moto while pushing hard the last half of the race to gain two positions before the checkered flag was waived.
Black Hills Sprint Enduro
Date: April 11, 2026
Class: Mini 4
Finish: 10th / 20
A demanding 45 minute event that tested both rider and machine while continuing to build confidence and racecraft. Diesel raced tough and maintained a steady pace the entire race. He made multiple passes in technical sections of the track and ended the race with another 10th place finish.
Ram Grand Prix
Date: June 28, 2026
Class: 250C
Finish: 12th / 13
Diesel’s debut race in the 250 class got off to a strong start before an uphill bottleneck of racers and a crash cost him valuable time and energy. Despite the setback Diesel fought back, finished the race in strong fashion and gained valuable race experience
Thunder Valley
Date: August 2nd, 2026
Class: 250C
Status: Preparing
Diesel’s focus now shifts to Thunder Valley, where he’ll look to build on his 12th place finish at the Ram GP. The goal is simple: keep training, keep improving and show up better prepared than the last time we lined up.
Douglas County Supercross
Date: September 12, 2026
Class: TBD
Status: Preparing
Derek is currently preparing for the Douglas County Supercross in Castle Rock, Colorado. Racing under the lights in our hometown will be a unique opportunity to test his supercross skills and continue building experience on a larger stage. The focus over the coming months will be on starts, cornering, jumps, and racecraft as he works towards lining up at this premier local event.
Team Updates
June 30th, 2026
Thunder Valley Practice Day
Every race weekend starts long before the gate drops. Practice days like this are where we test the bike, evaluate changes, and keep building Diesel into the best rider he can be. The goal isn’t just to ride faster it’s to improve every time we unload.
June 11, 2026
Training Begins with Matt Burris
Derek completed his first training session with coach Matt Burris. The focus was rider positioning, cornering technique, and building a strong foundation for long-term success.
June 9, 2026
SK Powersports Racing Adds KX450XC
SK Powersports Racing welcomed a 2021 Kawasaki KX450XC to the fleet. The addition expands the team’s training, testing, and competition capabilities while supporting the continued growth of the racing program.
June 7, 2026
KX250XC Race Prep Complete
Derek’s race bike received a major service and race preparation ahead of the summer racing season, including valve adjustment, coolant service, engine oil and filter replacement, brake fluid replacement, clutch fluid replacement, new front brake pads, and a new spark plug.
June 1, 2026
SK Powersports Racing Officially Launches
SK Powersports Racing was officially launched as a family-owned privateer racing program based in Castle Rock, Colorado. Built on a passion for motorcycles, racing, and hard work, the team is dedicated to rider development, race preparation, and representing the SK Powersports brand both on and off the track.
