THIS GOES ON THE CARBURETOR THROTTLE SHAFT ONLY . ////////////////// THIS IS BETTER THAN OEM REPLACEMENT PART. YOU SHOULD NEVER HAVE TO CHANGE THIS AGAIN UNDER NORMAL OPERATION USE. SO PLEASE MAKE SURE THIS IS THE CORRECT PART FOR YOUR APPLICATION. READ THE DETAILS AND LOOK AT THE PICTURES COMPARE THE OEM BLACK ROLLER TO THE WHITE ONE THAT IS FOR SALE.REPLACE YOUR ROLLER TO THIS STYLE TO PREVENT THE IGNITION TIMING FROM ADVANCING 3 TO 4 DEGREE'S TO PREVENT FROM BURNING PISTONS DUE TO THE TOO MUCH SPARK ADVANCE ALONG WITH RUNNING LEAN ON FUEL. AFTER INSTALLING THIS ROLLER KIT YOU NEED TO RECHECK THE TIMING PICK UP TO MAKE SURE THAT THE TIMING PICK UP IS CORRECT . YOU MAY HAVE TO ADJUST THE CAM ROLLER PICK UP TIMING.I MADE THIS REVISED KIT BECAUSE THE SLEEVES AWAYS SPLIT AND CAN CAUSE DAMAGE TO THE MOTOR.I HAVE SPENT A LOT OF TIME COMING UP WITH THIS KIT AND HAVING THESE MFG. .THIS IS NOT A OEM PART IT IS A UPGRADE. APPLICATIONS ON 40 48 50 HP THAT HAS THE TOP IDLE CIRCUIT COVER PLATE AND ON 60 70 88 90 112 115 150 175 185 200 225 105 JET  MOTORS ALONG WITH MOST ETEC MOTORS FROM 30 HP THRU 250 HP. THIS IS A BETTER PART THAN THE FACTORY REPLACEMENT THAT YOU HAVE TO CHANGE MANY TIMES. AGAIN YOU WILL NEVER HAVE TO REPLACE IT UNDER NORMAL CONDITIONS DUE TO THE OEM PART WHICH THE SLEEVE ALWAYS SLITS AND BREAKS. WILL SHIP USPS  MAIL