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1974 CZ 250 AHRMA Racing Photo Gallery
AHRMA races are only five laps so a smaller, thinner fuel tank was manufactured to make more room for the rider to move around.
We borrowed a 1974 CZ 250 classic dirt bike from Steve Machado to race in an AHRMA vintage motocross race.
A 60-tooth rear sprocket puts down power.
The hardest thing to get used to were the weak brakes and skinny footpegs.
Machado welded the off-set spark plug hole, filled the head and reground the dome like a modern two-stroke for consistent fuel squish. Then he punched a new spark plug hole in the center for more efficient fuel burning.
Suspension travel is unchanged to match the VMX rules, but the swingarm has been lengthened nearly two inches for a slightly longer wheelbase.
A 36mm carburetor feeds the engine and has been dialed in exceptionally well.
The shift throw is huge, making gear changes an action that requires the entire leg to move.
Drum brakes front and rear but the tires are modern Bridgestone M403/404.
Works Performance Suspension dialed in the shocks for the Moto Jam with lengthening spacers.
This restored warrior was eager to please and a very competent vintage racer.
The clutch has a monster pull that quickly wears out a rider's arm.
Even the tech guy slobbered over the 250 and peppered us with questions about such clean modifications.
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