Ok, I've been waiting to do this mod on my 02 YZ426 for some time now and haven't really seen anyone post on this board on how to make a 1/4 turn throttle. This is a very popular mod on sportbikes and it's a must have on my trackbikes. I've done a 02 R6 and a 01 R1 and it makes a world of difference in how quick you can turn the throttle and doesn't put you arm in a strange position when going full throttle. If you have a spare throttle tube I would suggest giving it a try and let us know how you like the mod, you will be amazed at how much difference the bike will feel after you do the mod. You may notice on a stock throttle to get every bit of full throttle you end up with your wrist in a strange position unless you start with your elbow sky high. Now that I have done the mod on my track bikes I've had a real tough time finding the stock YZ throttle acceptable. Here's what you have to do 1. Take off throttle tube assembly, duh. 2. Here is a pic of the stock diameter tube. 3. What you need to accomplish is increase the diameter so when you twist the throttle it is actually pulling the cable further since the tube has a larger diameter. 4. To increase the diameter of the tube go to home depot and purchase a PVC coupler (I believe 1 1/4"). approximately $0.37 5. Measure the width of your cable guide. see pic. 6. Cut the PVC coupler a few mm larger than the width of the guide. 7. Use 100 grit sandpaper and smooth the edges of the PVC piece and make sure to get approximate width correct. 8. Once you get close to the approximate width you need to test fit the PVC piece on the throttle tube making sure to cut the approximate amount to allow the PVC coupler to fit flush with the tube. 9. If you are satisfied with the fit, I would sand a nice transition on the throttle pull side so the throttle will have a nice smooth throttle reaction, this will very depending upon how much you smooth the PVC. Take a look on the really expensive custon aluminum throttles and you get the idea. Alsocut a slight slot in the return side so the cable fits nicely, you'll understand when you put teh cable back on what I'm talking about. Take a look at how the PVC rolls into the throttle tube on the lower right. 10. Now it's time to cut the internal tabs off of the throttle housing with a dremel. With the larger diameter throttle tube the PVC WILL HIT the tabs on the throttle housing and bind the throttle action, not good. Cut these small tabs off. With tabs... Without tabs... 11. Before you glue the PVC to the throttle tube be sure to test fit the throttle assembled to ensure the throttle doesn't bind. 12. Now you are ready to use 5 min epoxy to glue the PVC to the throttle tube. make sure to leave a little extra on the cable side so when the glue hardens you can sand the edges perfectly smooth. 13. After everything is dry I would adjust the cable tension to the loosest setting on the carb. Note if you don't do this before you install the assemble you will have a really difficult time adjusting the throttle play. 14. Assemble the throttle tube with the cables and install on bike.... 15. Adjust throttle cables and make sure you have enough free play and go out and enjoy a faster, more responsive throttle, without the extra wrist twist... Total cost of mod 1. PVC coupler $0.37 2. 5 min epoxy $3.00 One of this best mods you can do for under $5. Heck if you don't like the mod go to ebay and buy a stock tube for $10 and you're back to stock. Do this mod at your own risk.