Base jetting with Wiseco 13:1 piston

[mymastifftucker]

I am looking for a baseline jetting setup. I can fine tune it after....complete setup is in my sig.- 13:1 Wiseco piston. stg.2 hotcam, full Sparks exhaust, pro-design intake with the pro-tec airbox lid, and a dynatec FS programable ignition. Can I use the stock needle and just lower the clip, or is there a significant advantage to a aftermarket needle?, lastly, am I going to have to change anything besides the main jet and air/fuel setting? This is on a 2004 450R with the stock carb. Thanks in advance!!

[ghott]

I would go with:

Between a 180-190 main
Between 2.5-2.75 turns out on the A/F screw
48 (stock) Pilot/Slow jet (maybe a 50 pilot)
You might be O-K with the stock needle on the 3rd or 4th clip. (See how it runs mid-throttle).

For the slow circuit....if she pops on decel...keep screwing the A/F screw out until the A/F screw is a total of 3 turns out. If the bike is still popping on decel, return the A/F screw to 2 TURNS OUT, and bump the pilot jet from a 48 to a 50. Repeat the process until the popping is cured. (Remember, an exhaust leak can cause popping on deceleration as well...be sure to check for any leaks before fine tuning your jetting).

I would highly suggest purchasing the HRC Needle for more accurate fuel delivery. If you do decide to purchase the HRC Needle, use the 3rd clip....nuff said :).

Hope this helps.

[400exrider707]

Originally posted by ghott
I would go with:

Between a 180-190 main
Between 2.5-2.75 turns out on the A/F screw
48 (stock) Pilot/Slow jet (maybe a 50 pilot)
You might be O-K with the stock needle on the 3rd or 4th clip. (See how it runs mid-throttle).

For the slow circuit....if she pops on decel...keep screwing the A/F screw out until the A/F screw is a total of 3 turns out. If the bike is still popping on decel, return the A/F screw to 2 TURNS OUT, and bump the pilot jet from a 48 to a 50. Repeat the process until the popping is cured. (Remember, an exhaust leak can cause popping on deceleration as well...be sure to check for any leaks before fine tuning your jetting).

I would highly suggest purchasing the HRC Needle for more accurate fuel delivery. If you do decide to purchase the HRC Needle, use the 3rd clip....nuff said :).

Hope this helps.


How does an HRC needle offer more "accurate" fuel delivery???:confused:

[ghott]

Originally posted by 400exrider707
How does an HRC needle offer more "accurate" fuel delivery???:confused:

Needle taper...there is a difference between the stock 42mm Keihin carb needle and the HRC Needle.