needle position and location question

loudhvx wrote: I'm not sure if you guys can see the text on those drawings. I'm on a work computer and the second diagram is unreadable. Has anyone figured out a way to get the images to show up in the thread at full size?
I know you can drag and drop to the desktop and see it, but that gets old.

loudhvx wrote: There are at least three needles in most carbs:
Fuel inlet needle valve.
Air/fuel mixture screw needles.
Slide needle.

"Clip position" is meant for the slide needle. That (as was mentioned) is in the top part of the carb. Some needles are adjustable, some are not. The ones that are adjustable have multiple grooves cut into the top end where an e-clip snaps on. The ones that are not adjustable will have only one groove, or a permanently affixed clip.

Most carbs are such that raising the clip position lowers the needle, which makes things leaner. You can also put a shim washer on the bottom of the clip to raise the needle a half-step (richer). (Sometimes the needles are held in a way where the shimming is done on top of the e-clip instead of underneath it. In that case, adding a shim lowers the needle making things leaner.)

Sometimes, as in the case of the KZ550 Tk-22 carbs, there really isn't room for a shim in the needle-retaining assembly. You can force it in there, but you may possibly damage the needle or needle-jet due to capturing the needle ridgidly which leads to the needle scraping the needle-jet. The needle should have a slight amount of wiggle room, and almost no play up and down.

Here are some drawings of the needles for KZ550's. Note the stock U.S. one has only one groove and is not adjustable. The non-U.S. models had adjustable needles with 5 grooves. The Dynojet version of the needle has 6 grooves.

Clip positions are counted from the top of the needle.

Here is a drawing of how the needle relates to the main jet and slide.