Fairly new here and I was having the same problem idle and taking off from a dead stop. Just picked up this bike for my daughter.
This seems to be a common problem from the posts here. Already I feel this is mostly a valve adjust issue. Found my exhausts had no clearances. Intakes OK. Seeing as this bike needs checking every 4K, I think this is a neglected item for most.
I also see the spec's called out for the clearances are too small although I see them posted differently. If the manual says .03-.08mm, this is just too small on a air cooled bike. I've also seen it posted as .003-.005" which seems to be better clearances.
.03-.08mm is actually .001 to .003". I'm going to set mine at .003-.005" which is .08-.13mm.
I've gone through the rest of the bike and all seems good and I'm sure this will correct the running issue.
Will post later to confirm after I get my shim tool and new shims.

Quote from: ace50 on June 23, 2014, 08:25:42 AM
Fairly new here and I was having the same problem idle and taking off from a dead stop. Just picked up this bike for my daughter.
This seems to be a common problem from the posts here. Already I feel this is mostly a valve adjust issue. Found my exhausts had no clearances. Intakes OK. Seeing as this bike needs checking every 4K, I think this is a neglected item for most.
I also see the spec's called out for the clearances are too small although I see them posted differently. If the manual says .03-.08mm, this is just too small on a air cooled bike. I've also seen it posted as .003-.005" which seems to be better clearances.
.03-.08mm is actually .001 to .003". I'm going to set mine at .003-.005" which is .08-.13mm.
I've gone through the rest of the bike and all seems good and I'm sure this will correct the running issue.
Will post later to confirm after I get my shim tool and new shims.

Sounds like it should fix your issue as well.  My bike has just over 10k miles, and the shims I removed were factory stock (272s on intakes and 278s on exhaust), less than .0015" for all clearances.  It definitely seems to be a neglected item, and I can see why (a bit more effort than changing the oil).  Hopefully running the wider clearances will help them stabilize, and according to GSJack and others that has been the case.

I got 270 and 265 shims to get mine in order, and I got the shim tool off amazon.  FYI, I can't imagine trying it without the tool, or with a makeshift tool.

Edit:
I really wonder how many people spend a bunch of time working on their carbs for idling issues when it's truly caused by tight valves?  My carbs were almost pristine.  Even an ME friend of mine who does a lot of work on his own cars was surprised to learn that shims need checked/replaced so frequently on motorcycles.  Everyone I told about replacing my valve shims seemed to take that it was a serious overhaul or that I'd bought a lemon or something.

ace50, the Suzuki .001-.003" valve tolerance is OK  for intakes but not enough for exhausts which run too hot at the Suzuki .001" minimum spec.  The tighter exhaust on my 97 required constant shim changes and was down to a minimum thickness 215 shim at 80k miles with no place to go.

When the tighter exhaust valve on my 02 started the same pattern at about 30k miles I started setting exhausts at .003-.005" and after a couple adjustments it settled down and went another 40k miles without a shim change.

I've never checked valves at 4k intervals, started out checking them twice a year on my 97 which was about 8k mile intervals.  On my 02 riding less miles now I've  checked them once a year at about 10k intervals and declining.  Doubt they even need checking again now and at over 100k miles I've made my last valve check I hope.  Here's the whole record:

http://img.photobucket.com/albums/v443/jcp8832/GSvalvelogs_zps9ef7236a.jpg

Quote from: DoktoroKiu on June 23, 2014, 09:13:13 AM

Edit:
I really wonder how many people spend a bunch of time working on their carbs for idling issues when it's truly caused by tight valves?  My carbs were almost pristine.  Even an ME friend of mine who does a lot of work on his own cars was surprised to learn that shims need checked/replaced so frequently on motorcycles.  Everyone I told about replacing my valve shims seemed to take that it was a serious overhaul or that I'd bought a lemon or something.

Good post!

Quote from: gsJack on June 23, 2014, 09:50:11 AM

I've never checked valves at 4k intervals, started out checking them twice a year on my 97 which was about 8k mile intervals.  On my 02 riding less miles now I've  checked them once a year at about 10k intervals and declining.  Doubt they even need checking again now and at over 100k miles I've made my last valve check I hope.  Here's the whole record:

A bike with higher mileage will take less shim adjustment cause the valves have seated more and now have a larger contact surface.
That's not really a good thing as it affects air flow. But unless you want to rebuild it, that's what you got, and back to checking it more often.

I got this bike for my daughter and she'll never ride as much as I do, but I'll never have an air cooled bike myself. That includes Hardlys.

Huh?  I give up!

Quote from: ace50 on June 23, 2014, 08:25:42 AM
Fairly new here and I was having the same problem idle and taking off from a dead stop. Just picked up this bike for my daughter.
This seems to be a common problem from the posts here. Already I feel this is mostly a valve adjust issue. Found my exhausts had no clearances. Intakes OK. Seeing as this bike needs checking every 4K, I think this is a neglected item for most.
I also see the spec's called out for the clearances are too small although I see them posted differently. If the manual says .03-.08mm, this is just too small on a air cooled bike. I've also seen it posted as .003-.005" which seems to be better clearances.
.03-.08mm is actually .001 to .003". I'm going to set mine at .003-.005" which is .08-.13mm.
I've gone through the rest of the bike and all seems good and I'm sure this will correct the running issue.
Will post later to confirm after I get my shim tool and new shims.

Yep, proper exhaust valve clearances fixed the hanging rpms when blipping the throttle. Returns to idle like it should.
Lost a day of work cause I grabbed a can of old gas to start it back up and ran like sh_t! Took a little while find out what I did.
Installed a Hiflow filter too and now I'm lean off idle. Just need bigger pilot jets - to start with.

Good to hear this fixed your problems as well.  I won't hesitate to recommend checking valve clearances to anyone with any type of low/high idling problems.

I'm actually going to have to tear into mine again because the valve cover gasket is leaking a bit of oil now.  I had one small tear on the outer edge of the gasket I figured I could get away with patching with RTV, but nope.  Replacement gaskets on the way for the cover and breather gaskets, as well as all those little O-ring gaskets for the valve cover bolts.

Might also grab a small beam-style torque wrench to help get the bolts tightened this time, because last time I had to re-torque them after a few rides because they loosened up (paranoid about over-tightening I suppose).