Hanging throttle?

warrenlevihursh

XS650 Addict
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Just timed my pamco and adjusted valves. My advance springs back like it should, but my throttle hangs only when I rev it up and hold the rpms up. It doesn't hang if I just blip the throttle quick. It drops nice and quick. What is this indicative of? Jetting or needle position in the carb? I also couldn't find any air leaks. Thanks.
 
What carb?
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Thanks for pics!
Just from hearsay, you might want to pull the slide, get some really fine paper like 1500 or 2000 grit and look for rough spots.
 
Yes, those are Keihin PWK Chinese knock-offs and there have been quality issues reported with them.
 
They're had quality control issues and the parts not fitting together right. Slides hang up and sometimes floats do too. Hard to tune a carb like that, lol.
 
I've got two xs 650's with single 36mm Mikunis and they both had the hanging throttle problem until I wound another return spring together with the original one for extra closing force. There is more vacuum with the single carb set-ups. Fixed mine perfectly. Mikuni had light and stiffer springs you could get at one time but I do not know if they still do.
 
I've got two xs 650's with single 36mm Mikunis and they both had the hanging throttle problem until I wound another return spring together with the original one for extra closing force. There is more vacuum with the single carb set-ups. Fixed mine perfectly. Mikuni had light and stiffer springs you could get at one time but I do not know if they still do.
This makes a ton of sense. I'll have to see if I can find another spring somewhere. Thanks.
 
Just put the stock carbs back on, but if not you will eventually figure out what it will take to run the carbs .
 
UPDATE: I did find the cable worked its way loose out of the throttle housing. This seems to have helped the random RPM changes. I also fattened the pilot and main way up. 40 to 48 on pilot and 110 to 170 (all I had) on the main. I could prob even go bigger on the main. The bike actually runs good and doesn't run out of fuel now on extended full throttle pulls up hills.
 
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