FITS THE FOLLOWING ORIGINAL ENGINES: CT90'S K5, K6, AND 1976 TO 1979 ALL YEARS OF ST90'S ATC90'S WITH A ENGINE SERIAL NUMBER'S LARGER THAN 1113934 OR ABOUT 1972 AND NEWER ============================================== Hey Jack, I just wanted to give you a status update. I have about 250 miles on the 120cc kit, it's great fun. If someone is in Denver or similar elevation and they want to use the stock carb with the altitude adjuster, the best settings are: 35 pilot jet 72 main jet needle on middle shim 1.5 turns out on the air screw I can get over 50mph on the flats and I'm 260lbs. Larger jets run too rich at my altitude and the engine's hot enough I wouldn't go leaner. I understand the 22mm carb will breathe easier but at my weight 50mph is spooky enough and I have other bikes for pure speed. The CT geometry seems happiest at 40mph and your kit's given it outstanding grunt for such a little bike. Thanks again for creating such a cool kit for the bike! - Eric N @ _ "DIY" NEW TYPE OHC90 HEAD/CYL 120cc "SLEEPER" STROKER CRANK CORE KIT READ FITMENT CAREFULLY (273L/253K/335T/296N/296N) exed sorry discontinued 273L/253K/335T/296N/296N @ PLEASE CLICK AND READ THIS BEFORE BUYING @ CRANK PIN INSTALL INSTRUCTIONS @ PIN ARROW POINTS UP @ BOTTOM END ROD CLEARANCE/GAP .004" @ RING INSTALATION SEE PIC / PISTON TO CYLINDER CLEARANCE .001" TO .002" @ THE CHARACTER SIDES FACE TO THE TOP OF THE PISTON DOME MAKE SURE THE GASKET POINTS DON'T GET IN THE WAY OF THE STUD HOLES @ FIY @ FIY @ FIY