I've Owned A Solo 680 For A Couple of Years Prior to Being Stolen While Living in *s-word's Ville Stockton Ca. ( Amazingly """ NOT """ The Worst Place in California Anymore !!! ) and it Had The Automatic Decompression Valve. It Worked Most of The Time,,, But When It Didn't... It Was Very Unpleasant. It Was Replaced With A 690 With a Conventional Decompression valve. Hot Or Cold, You Have To Use It For Every Pull Of The Starter, Or It Will RIPP The Starter Out of Your Hand, or Damm Near Dislocate Your Shoulder """ Or """ Both When It Pops Off In The Middle of A Starting Pull.... They Have The Longest Stroke Of Any Modern Saw, And Stupid Compression. There Not Super High Reving, BUT !!! They Won't Stall Either.