I wrote this post
over on my personal blog about the "quick throttle" mod I did, and figured I would share this here.
The stock throttle tube on the 2003-2011 CBR600RR is 1/4 turn or 33.8mm. Most people when looking at changing to a “quick turn” throttle use the Yamaha R6 throttle tube, which is 1/6 turn or 40.5mm.
Another option is the HRC throttle tube. If you’re after a 1/5 turn the Yamaha R1 throttle tube is also an option. I decided to use PVC coupling and once completed measured up at 40mm. I guess you could buy the R6/R1/HRC throttle tube, but it will be more expensive.
33.8mm (1/4 turn) – CBR600RR Throttle Tube (2003-2011) – Part: 53140-MCF-000
36.5mm (1/5 turn) – Yamaha R1 Throttle Tube (2007-2008) – Part: 4C8-26240-00-00
40.5mm (1/6 turn) – Yamaha R6 Throttle Tube (2006-2009) – Part: 2C0-26240-00-00
40.5mm (1/6 turn) – HRC Throttle Tube – Part: 53141-MT7-000
Tools You Need
- dremel or some sort of small cutting and sanding tool
- socket set / screwdrivers
- 25mm PVC coupling
- service manual
To obtain the needed slack on the throttle cables for the larger diameter cam you will have to create more at the throttle bodies, also wind in your throttle cable adjuster at the housing too which will allow you to create as much slack as possible. So with this in mind open up your service manual and get to work. You will need to remove the ram air duct covers, tank cover, prop tank up, remove the ECU, air box lid, velocity stacks and air box. The task seems daunting, but should be able to get to the throttle bodies in about 15 – 20 minutes.
This is what the stock throttle cam looks like.
1. I used my dremel to cut the end off of the fitting a little wider than the actual width of my throttle cam.
2. I cut a section out of the PVC loop to fit over the throttle cam. I used the sanding wheel to “scuff” the inside of the PVC then cleaned it with some isopropyl and glued it onto the throttle cam. After the epoxy set, I used my grinding wheel to make the PVC the same width as the throttle cam and tapered the PVC to allow the cables to run smoothly.
3. I used the sanding wheel on my dremel to smooth the edges of the PVC are perfectly smooth so that way it wont bind to the housing, and cleaned with isopropyl alcohol.
4. I had to use my cutting wheel on my dremel to make the throttle housing bigger to fit the larger cam in. I’m not sure if the newer model 600rr needs this but I know the housing on my 2003 model needed it. I took a few millimeters off the inside of the top and bottom of the housing. Then I connected the throttle cables up to the cam, and tightened the nut at the throttle bodies.
Before reinstalling make sure you check for any binding, and confirm the nut at the throttle body is tight. Putting back together is the reverse of pulling it apart. Then readjust your throttle free play if you have any. I like to have virtually zero play.
So that is the “quick turn” throttle mod for my 2003 CBR600RR. If you’re attempting this mod, you do so at your own risk. I will not be held responsible for any mishaps that may happen by doing this mod.