James Dean Jetting Kit Now Available For WR400/426/450
Posted July 02, 2003 - 01:25 PM
Posted July 02, 2003 - 04:15 PM
Posted July 02, 2003 - 04:48 PM
Posted July 02, 2003 - 06:15 PM
I just got my confirmed UPS shipment tracking number. I should have it next week!
Its actually a US Postal Service (USPS) delivery confirmation number. We ship these priority mail (2-3 day delivery including Saturdays.) You should receive the kit on Saturday, Monday at the latest.
Posted July 02, 2003 - 07:52 PM
The kit has a very good standard setting to start from. This setup will work in most WR's and YZF's with no need to change any other jets in the carb and take a big jump in performance. Modifying the exhaust and cam timing will work well with the standard setting, and better with fine tuning. Use the same instructions to start with.
The intent here is to give you a jetting kit that I would want myself.
---If a rider wants to make the installation and just go ride, it's a simple change with all the parts and instructions for a wide range of conditions.
---If a rider wants to maximize performance, the 2 needles and the range of main jets will give the most gains you will find on a modified bike with some careful test runs.
I have all the needles from tapers Cxx, Dxx, Exx, and Fxx to diameters xxL, M, N, P, Q, R, S, T, and NCVN, NCVP, and NCVQ. All these needles were run at different times and compared before launching into the design of the kit's triple taper needles. Each throttle range from 0-1/4-1/2-3/4-full was tested over and over to decide what diameters and tapers would give the best performance. It wasn't made by focusing on any single condition. The jetting comes from riding for weeks and keeping notes on every test and a wide range of conditions. It's been tested from sea level to 12700ft and dyno tested on the KTM 400 to confirm the needle effects on full throttle.
If you have ever read the "Jetting Q's", there are so many aspects that go into developing high performance jetting that it takes careful evaluation. Taffy has some great suggestions on pilot air jets and needle design. The kit does not suggest changing any pilot jets or pilot air jets. The stock pilot jets are recommended with the kit. Most riders want a quick and simple correction so they can go ride with a performance gain and minimum amount of work. Yamaha developed the low speed jets to work together and I'm going to defer to their settings in most cases. The richer kit needle will offset lean conditions in the same way an EMM or EMN needle will. The Leaner needle in the kit will also match idle and off-idle response with --P and --Q stock setings.
I know this is too much technical detail for most riders. The bottom line is the jetting kits are designed to make a quick and inexpensive performance gain with potential for more than any stock parts can deliver.
Posted July 05, 2003 - 02:16 AM
I'm goning to order a kit Monday.
Posted July 16, 2003 - 09:29 AM
OK, I just ordered the kit and already got the confirmation number I was wondering if you could give me the settings I will need to try when I get the kit. I know it comes with instructions, but I am not sure if they are based on a stock bike or if it includes various settings for different mods. My bike is an 02 WR426 with a Baja Designs Baffle, and airbox snorkle removed. I ride (dual sport, trails) in Michigan at about 500-1000ft. Temps around 80 (average). What would you suggest I throw in and set everything at once I get the kit? I don't want to keep changing things once in so your recommendations are appreciated.
Posted July 16, 2003 - 09:43 PM
I would suggest using the kit settings described with blue marked needle clip #4 and #168 main jet(for insert baffle), stock pilot jet. Adjust the fuel screw as needed for low speed jetting. You might want to use clip position #3 for extra mileage on the dual sport rides too.
Posted July 17, 2003 - 02:18 AM
Posted July 18, 2003 - 06:53 AM
Posted July 20, 2003 - 01:40 PM
Posted July 20, 2003 - 02:36 PM
Posted July 20, 2003 - 03:44 PM
Posted August 06, 2003 - 05:29 AM
Posted August 06, 2003 - 09:41 PM