Vortex Throttle Kit, 01-0579 & 01-0580 (04 YFZ 450)
IMPORTANT - READ INSTRUCTIONS BEFORE INSTALLING
THIS KIT IS TO BE INSTALLED BY A TRAINED TECHNICIAN IN A PROPERLY EQUIPPED SHOP
THESE INSTRUCTIONS ARE FOR USE WITH TWIST GRIP TYPE THROTTLE KITS. THESE KITS ARE DESIGNED TO REPLACE THE ORIGINAL THUMB THROTTLE WITH A TWIST GRIP TYPE THROTTLE.
1. Remove the seat and fuel tank. Carefully observe how the stock throttle cable is routed from the thumb throttle to the carburetor. This is how you will want to route the new cable.
2. Temporarily remove any clamps or guides used to retain the throttle cable. Remove the stock thumb throttle assembly and disconnect the 2 wire plug from the wire harness and install the switch elimination coupler assembly to the wire harness. This will provide a "closed circuit" allowing the machine to operate correctly.
3. Note: On stock carburetors the throttle cable is connected to an internal bell-crank, it is not necessary to remove the carburetor cap or slide, just remove the bell-crank access cover to complete the cable connection. ANY DIRT OR FOREIGN MATERIAL THAT ENTERS THE CARBURETOR CAN CAUSE THE THROTTLE SLIDE TO STICK.
4. Remove the right hand grip from the handlebar. With the Allen wrench supplied, disassemble the new throttle assembly. Using the throttle sleeve as a guide, mark the handlebar showing where the sleeve will fit. With fine sandpaper remove any paint on the handlebar where the throttle sleeve will fit. IT IS VERY IMPORTANT THAT THE HANDLEBAR BE CLEAN AND SMOOTH. IF THE HANDLEBAR IS NOT CLEAN AND SMOOTH IT IS POSSIBLE FOR THE THROTTLE TO STICK.
5. The type of twist grips vary, but all types will install and work similarly. Slide the throttle sleeve onto the handlebar. Next, install the cable through the top half of the throttle housing and connect the cable end to the slot in the throttle sleeve. Install the plastic cable guide or wheel into the upper throttle housing. Make sure the cable fits into the groove of the guide or wheel. Note: Some throttle designs do not have plastic guides or wheels. Refer to individual throttle instruction sheets. Assemble the upper and lower throttle housings while positioning the throttle sleeve stop above the housing stop. Allow an 1/8 inch clearance between the grip and handlebar end. This will prevent the grip from binding on the end of the handlebar. Position the throttle so that the throttle cable will exit above the front brake lever assembly. Insert the throttle housing screws and tighten.
6. Throttle cable adjustment: ALL THROTTLE CABLE ADJUSTMENTS ARE DONE WITH THE ENGINE OFF. Adjust the throttle cable so there is a slight amount of free play (1/16 to 1/8 inch). Tighten all adjuster nuts. Reinstall all cable clamps and guides. Check that the throttle will snap back from the full open position in all handlebar steering positions. Also, check that the cable has free play when the handlebars are turned side to side. Note: Cable routing and throttle position affect the smoothness of throttle operation. Route the cable to avoid sharp bends or kinks. Position the throttle so that it does not create sharp bends or kinks in the cable.
7. Install the fuel tank and seat. Start the engine to check throttle operation. Using throttle, raise engine speed momentarily to 4000 RPM and release throttle. Engine speed should drop quickly to idle speed without hesitation. Next, while turning the handlebars side to side, there should be no change in engine speed. Repeat, Step 8 if throttle is not operating as described above.
8. It is suggested that you familiarize yourself with the operation of the twist grip throttle. Run the machine at different speeds until you are completely familiar with how the throttle operates. If you have experience riding motorcycles the twist throttle will be quite natural. If you have only used the thumb type throttle you should practice until operation of the twist throttle is done without second thought.