click upper image to enlarge    Torsten Hallman  July 12 2005   Lake Forest, Illinois

  The center cases are based on the DT1, while the clutch cover is sand-cast magnesium.  The transmission uses hand cut gears that are drilled for lightness and the clutch basket is machined from billet aluminum.  As on the Husqvarnas Torsten shifted his bikes from the right side.  The kick start lever is forged titanium.

 This is the first reed valve cylinder.  If you look close you can see the weld buildup to house the reed cage.  It was made from a piston port works cylinder.  The cylinder is chrome bore and the porting layout is much different than anything Yamaha offered at the time.  Notice the hand fabricated brake pedal that is actually mounted on the titanium swing-arm pivot.  All the motor mount bolts are machined titanium.

  The spark is generated by a points ignition with a very small inner rotor.  The revs build up instantly.  All the coil windings are wound special just for this bike.

  The air-box is a custom one fabricated by Torsten.  The stock one wasn't up to the job.  Torsten also took some packing foam that the bikes came in and made a sock that went over the original filter for extra protection.  A man by the name of Mr. Bob Tuin (pronounced twin) was there that day and took Torsten's idea and started a company called Twin-Air!

  Looking at the rear of the bike gives one a sense of just how trick and handmade this bike really is.  It is the original prototype YZ.  The seat is not recovered, it is an original new one from 1971.  The seat pan is hand pound from steel. Check out the special washers at the rear of the seat.  There were no silencers in those days.  This bike is real loud!  Even the fenders are vacum-formed.

         click either image to enlarge

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