MX HISTORY: THE YZ400 TWO-STROKE - Dirt Bike Magazine
STUNNING 1984 YAMAHA YZ490 BROC GLOVERS 85 A.M.A. NATIONAL CHAMPIONSHIP WINNING MODEL; FAST & FUN!! - YouTube
Dirt Wheels Magazine - YAMAHA TRI-Z 490 In honor of 3-wheeler Thursday Robert Boyter stuffed a big YZ490 engine into his Tri-Z 250 frame. Be ready to hang on when you hit