My problem is probably similar to that reported at
http://www.gstwins.com/forum/viewtopic.php?t=14815
but I don't think that ever got resolved either.

This started happening slowly, and now it's pretty consistent and worse.  Regardless of gear, in the 6-7.5K range on the tach the bike's doing some coughing, like lean misfires.  It does smooth out above there.  The local mechanic has tried various jet sizes (pilot and main), including stock and Srinath's prescription, and it still does it.  We even tried some way-too-big jets for laughs and got a variation of the same trouble, though it was interesting what that seemed to do down low!  (Fun)  Plugs don't seem to indicate anything radically off-normal happening.

Oh, it also surges when warm.  I used to have the idle WAY down because otherwise, off the highway, it liked to do 3.5K's.

He's going to try messing with the jet needles next.  They were replaced not that long ago, as I got a carb rebuild kit and he also put in the jet needles and needle jets for good measure (well, I bought them anyhow).

At the time he also adjusted the valves.

He's done the WD40 air leak test, and made sure of float levels (I think).  The bike has stock exhaust and air filter type.

I'm wondering if anyone has any other ideas.  I'm ready to sell it to a dealer if I can't get it fixed.

--Mike D.

Man the same old question when it comes to this bike. My problem turned out to be fuel starvation at 60 mph due to pitcock just a little bit turned wrong at the tank, and or oring under the emulsion tube bad. If yours came on slowly..... I've read many many posts on this forum and theres a lot of different answers to this same problem. One member resolved his problem by running 2 tanks of fuel with cleaner/ additive and his problem went away after about a week. Indicating gummed fuel system. I also had to raise my needles by adding 2 #4 washers under there. I have stock exhaust and airbox and paper filter. If you reference my post "paging the carb wizards" I just spent a week working on my bike for a very similar problem. I list what all I've done.

OK so what's the needle set to ... washer ... 1 or 2 ... and air screw that 3.5 K idle seems to be air screw ... the rest seems to be needle ...
Cool.
Srinath.

Thanks for the replies.  I'll send all this along.  The needle was going to be his next thing to mess with.  I read through that whole other thread.  Good to know that there are a few non-obvious things that could be giving me the trouble.  Hopefully it will all get sorted out and I can fall back in love with the bike.  I'll let you know about any other developments.

Thanks,
Mike D.