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03 XR70 throttle valve won't align...

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So, I went through daughters carb on her 2003 XR70 just to clean it up. Upon startup I quickly realized that it wouldn't idle... runs good, but won't idle. I atempted to adjust the idle screw and the throttle locked. I know this wasn't good, so I killed it, backed the screw off, freeing up the throttle valve, and took carb apart again to finder that there is no guide (post, tang, etc...) for the valve plunger to slide along so that it comes to rest on the beveled indentation for the idle screw. Instead, after a throttle twist, the valve plunger rotates slightly enough that the idle screw catches the very bottom end of plunger, completely missing the idle ramp opening, causing the motor rack out at full throttle. It doesn't even look like there was ever a guide of any sort in there at all. I don't see any other way to make it work without having some sort of guide. Have I lost my damn mind, or do I have to buy a new carb for $110?

Edited by Jon Palmquist
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The guide is typically a nylon 'pin'. If you soaked the carb in strong solvent, the pin might of dissolved. You 'might' be able to fabricate a new one. It is not a service part normally, so you'd have to find the material of the correct diameter, and cut and fit it.

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