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Old 10-12-2012, 12:31 PM   #70151
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Joined: Feb 2006
Oddometer: 2,856
Originally Posted by neo1piv014 View Post
The PO said he pit a DJ kit in there so it might have happened then.
If the jet needle does not have more than one clip groove, it's not a DJ needle. Is the white needle spacer installed under the clip? If so, is it round, without a notch or being d-shaped?
I didn't see any kind of noticeable wear on my Carb parts that made me concerned. What exactly should I be looking for?
The rubber tip of the float needle should be inspected under magnification. It should perfectly conical, with no witness line evident where it was contacting the seat. If any evidence is visible, or if there is a gap between the bottom edge of the rubber tip and the aluminum portion of the needle, if the plunger is stuck, or if the plunger return spring is sacked out, the needle should be replaced. Not doing so means that the float valve is leaking, or will begin leaking soon.

Emulsion tube wear generally sets in rapidly when the slide guide has worn .010" or more. The way to tell is to measure the depth of the depressions that are located in the bottom corners, concentric to the bore. If they are .010" deep or less, the slide guide should be replaced. '96 and up DR650 emulsion tubes are nickel plated, and so a bit more wear resistant than those found on previous models or KTMs. I don't know how thick the plating is, but if the nickel has worn away to expose the brass, it's definitely time to replace. Replace the slide if the lift hole area has been increased over stock, if there is vertical grooving on the downstream side, or if the needle hole is enlarged and/or ovaled.

See (scroll down for description and links. Click image for high-res view):

Slide guide, used
Slide guide, new
Emulsion tubes, new and used
Slide, used
Slide, new


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