Rider: Jake Alvarez
Photographer: Daryl Ecklund
Lens: Fixed f/4 300mm
F Stop: f/5.6
Shutter speed: 1/1600
TWO-STROKE SPOTLIGHT | KAWASAKI KX150AF
“This is the “2nd edition KX 125AF” built on a 2015 KX250F chassis I built. It got a fully built race engine. Here is a list of what I did to it:
-Ported cases with a VHM modified high enertia crank
-Cylinder is bored to 58mm and ported by Per Berg at PBR Racing
-Running KTM 58mm Big bore Vertex piston
-VHM cylinder head with 3 different inserts, 13.20cc, 13.40cc and 13.60cc designed by PBR racing
-Kehin PWK38 airstryker carburator
-Vforce 3 intake
-HGS 144cc exhaust
-Two different HPI CDI boxes, on for pump gas and one for 102 octane pump gas. Both got 2 curves to choose from via handlebar switch
-Clutch is complete Hinson but with a Prox innerhub
-Showa front fork, rebuilt by Kumlins suspension (http://kumlinsmotor.se)
-Fox Podium RC3 shock, rebuilt by Kumlins suspension
-Xtrig 21-23mm offset triple clamps with PHDS bar mount
-Renthal Twinwall 998 handlebars
-Moose racing DC8 levers
-Renthal kevlar grips
-Graphics are made by “Made” (http://www.made.se/sv/)
-Enjoy ribbed seat cover (Not pictured)
-Pirelli MX32 tires
Editors Note: Please keep those submissions coming. If you would like your bike to be featured on the MXA website, please email the Managing Editor Daryl Ecklund at email@example.com. All we ask is that you give a breakdown of your bike and a detailed description of the build. Please also send a few photos of your steed. By submitting your bike for the “Two-Stroke Spotlight,” you agree to release all ownership rights to the images and copy to MXA.
THIS WEEK IN MXA: TROY LEE’S SON TO BE THE TEAM MANAGER OF HIS TEAM
LOST BUT NOT FORGOTTEN | 1998 HUSQVARNA CR125
2023 AMA SUPERCROSS CHAMPIONSHIP BROADCAST SCHEDULE
MXA MOTO TRIVIA
MXA VIDEO: 2023 KTM 300 vs. HUSQVARNA 250 TWO STROKE
2023 WORLD SUPERCROSS (WSX) DATES ANNOUNCED—ALL SIX OF THEM
The 2023 FIM World Supercross Championship (WSX) will be six races long with events in France, Germany, Canada, Australia, England and a round in Southeast Asia to be announced at a later date. It is not the blockbuster race schedule that everyone expected to compete agaisnt the 17-round AMA Supercross Championship. The WSX does not start until after the AMA serie is over, and in fact, WSX starts after four AMA outdoor Nationals have been concluded. There are two dates with the 2023 AMA Nationals: July 1 versus Red Bud and July 22 versus Washougal, but there could be conflicts between the AMA SuperMotocross Playoffs in September and October because SuperMotocross has only confirmed one date for their three-race play-offs and is on the same day as the Dusseeldorf, Germay WSX round.
2023 WORLD SUPERCROSS CHAMPIONSHIP SCHEDULE
July 1…Birmingham, England
July 22….Lyon-Décines, France
Sept. 30…TBD (Southeast Asia)
Oct. 14…Dusseldorf, Germany
Oct. 28…Vancouver, Canada
Nov. 24-25…Melbourne, Australia
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MXA QUOTE OF THE WEEK // AUSTIN FORKNER TALKS BEING MAD ABOUT NOT BEING AS FAST AS JASON ANDERSON
Yes, by riding with Jason, it does not get much better. He won what, seven or eight races last year, nearly in a row in Supercross. It pisses me off whenever he is faster than me but then I am “okay, it is what it is.” If I can be within even a second or a second and a half of Jason, I am riding good! But it does piss me off because I want to go faster, and some days, I think “damn, I don’t know what he is doing different that he is going so much faster.” Obviously, he is on a 450, but there are little things that just by watching him, you can pick up on. It is always good to be pushed in the motos, and he likes doing them with me too. He comes up to me almost every day, ready to go. We try to link up and do stuff together. We push each other a little bit, and it’s less boring if you are doing a moto with somebody than just by yourself.
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MXPERTS // WHAT IS THE RIGHT OCTANE TO RUN IN A FOUR-STROKE? WE SAID IT ONCE WE’LL SAY IT AGAIN
What octane gas should I run in my Yamaha YZ250F? Should I run more octane to make it run faster? Will this hurt anything?
All production motocross engines are designed to run on the 91-octane American unleaded premium that can be purchased down the street (however, if you live in Europe, American 91-octane gas is equal to European 97-octane gas). If your engine can be put under a race load without detonating, you seldom find hidden power in higher-octane race gas. Octane alone doesn’t dictate how much horsepower an engine makes. Used properly, however, more octane can allow an engine to be tuned to make more power. Thus higher octane can be necessary if you hop-up your engine, especially on two-strokes. Additionally, there are race gas blends that add other elements and additives to produce more power — most commonly increased oxygen content.
In 1928, scientists developed a detonation testing machine. A single-cylinder, water-cooled, 612cc test engine was run 600 rpm as the compression was increased until the engine pinged. The highest compression value that resists detonation is assigned a number—called the Research Octane Number (RON); however, gasolines with high RON numbers aren’t suitable for high-load, high-rpm use. So, they ran new tests at 900 rpm and incorporated variable ignition timing—this was similar to sustained high-speed and high-load conditions. The rating from this machine is called a Motor Octane Number (MON), and it is always lower than the RON.
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CLASSIC MXA PHOTO
Moto Trivia answer: Jeff Leisk back in 1989. Below he is on the cover of the September 1989 issue of MXA.