What kind of mods require a change in the needle position?

[400exstud]

I was just wondering what the general area is that you can be in before the needle needs to be raised (clip is lowered).

Stock position should be good for a full HMF (w/ quiet core), K&N filter, lid ON, and a stage II hotcam, right?

Thanks

[GPracer2500]

I'm guessing stock postion is fine with that settup. You might be borderline depending on where you ride. You could always try moving the clip down a notch just to see the difference. Another option is to get a small washer the same size as the clip. Use the washer as a spacer to get "half-way" postions.

In my experience, environmental conditions (elevation, air temp, etc.) are just as likely to be the reason for needing a needle position change as most tuning settups.

Also, the overlap between carb circuits comes into play to a certain degree. When you richen your main jet to accommodate mods than you are also richening the jet needle circuit. The change in the jet needle circuit is small, but it helps account for why that circuit doesn't need quite as much attention as the main jet circuit.

[400exstud]

Thanks a lot.

Anyone else?

[Wheelie]

With a slip-on, K&N Filter, modded lid and no choke, I lowered the clip one notch and it worked great. Odly enough the same setting works great w/my stroker. I tried the bottom notch w/the stroker, but the mid range was too rich.