So, quick run down for those not in the know....
95 GS500, 9000 miles. K&N Lunchbox air filter, dynojet stage 3 jets, stock exhaust, size 40 pilot jets. Carbs were synced 2 weeks ago (although i didnt re-sync them when i put the pilot jets in) screws 3 turns out. 

I was on my way to work just now (after lunch, it looked like the rain would hold out so i figured..what the heck)
And about half way here, the bike started sputtering, and died. I switched to reserve, but it wouldnt fire back up. I had only been riding about....oh....1/2 a mile when it happened. Idle just dived and sputtered, then the bike shut off.
This occurred while i was sitting in line at a light. On a one way street. Right before it turned green. Needless to say, quite embarrassing.

I eventually got it started by messing with the idle adjustment screw enough to get it started again. Still, it wouldn't maintain a steady idle. And hung up around 3000rpm. Adjusting the idle screw down would drop the revs, but it would die again. I nursed it to work and am a bit worried about the ride home.

Also, the idle was super rough, popping too once or twice, but not steady. Float bowls have been checked, carbs cleaned, and synced just two weeks ago. Only put MAYBE 10 miles on it between then and now.
Very confused.
Help!

A few things to consider.

Did you ever check your valve clearances? 

I had much better luck after I replaced the old carb diaphragms.  Seems like the old ones were stiff or had a small leak, so they would move inconsistently. 

You might also consider replacing the vacuum petcock if it is original.  An original '95 petcock rubber is probably stiff and fuel delivery could be an issue.  Try running it on prime to get home and see if it helps.

Sure you got gas?

We has a good laugh after one person tried to fix the peacock problem last weekend only to look in the tank and see or not see much gas.

Quote from: adidasguy on April 25, 2012, 11:41:58 AM
Sure you got gas?

We has a good laugh after one person tried to fix the peacock problem last weekend only to look in the tank and see or not see much gas.

Yea and he was twice as embarrassed when the peacock jumped out from his bike and pranced around with a full on dance.
Here I managed to get it on my camera.
http://www.famushu.com/blog/fashion/peacock-dance/
Cool.
Buddha.

Sorry to say I don't think the idle screw has anything to do with it.  Also make sure the vacume hose to the petcock didn't fall off the carb.  That will starve you for gas plus create a heck of an air leak in the intake track on one side.

Yea, plenty of gas in there. About 1/4 full, which should be fine on reserve. I would think.

Valves are happening this weekend. But i had it running pretty good last week. Only thing i changed was the pilot jets.

Thanks for the petcock tip. I'll see if i can chase one down for cheap.

Quote from: cheetahman on April 25, 2012, 11:47:07 AM
Also make sure the vacume hose to the petcock didn't fall off the carb.  That will starve you for gas plus create a heck of an air leak.

Ooooooo another good one. I hadn't even thought of that, and its easy to check...

   Try on prime?

Quote from: adidasguy on April 25, 2012, 11:49:37 AM
  Try on prime?

Yes, i promise i will try it on prime on the way home. 

Lots of stop lights between here and there...will just a direct feed of fuel cause other running issues while at a light?

Nope not as long as the needles and seats are good.  Otherwise ,you risk an unplanned bike roast.

Well thats...uhm.....comforting.   

Some people mod their bikes so they get a direct feed of fuel on purpose.  This is how many bikes operate stock.  I replaced my petcock with one from a CRF250X which doesn't require vacuum.  I wouldn't worry about it.  As long as you have somewhat functioning needle valves, you will be fine.

Ok. Im really only about 1 mile from home, i usually like to take the long way if it have the bike (ie: the opposite way and around town till i decide to go home..lol) but i suppose i can make a bee line for home in this case.
I'll give it a shot.

Guys in all honesty I dont believe even the stock petcock (or peacock depending on your bike) setup can starve the bike.
Why do I say so so emphatically.

Do this experiment.

Fill tank.
Connect drain hoses to the carb drain spigots.
Put a gas can with 5+ gal capacity next to the bike.
Route the 2 drain hoses into it, open the drain screws.
Put petcock in prime and start your stop watch.
When fuel stops flowing or has manay many bubbles, or you have more gas in the can than you care to lift back and fill the tank with, stop the stopwatch.
I will bet you have under 15 mins oon that clock.
So ok 15 min to empty the tank.
You drained 4 gal in 16 mins lets say for being round numbers.

Lets say your bike gets 50 mpg, So you need to run @ an average of 200 miles in 16 mins to run the carbs out of fuel.

Any GS or any other bike too I ahve managed to starve for fuel while riding, has a much bigger problem. One had a sheet of news paper, another had a coating that came loose, third had a clogged fuel line etc etc.

Cool.
Buddha.

Sir, i have no idea what any of that meant, but i now have confidence that at least i shall not perish in a ball of purple fire on the way home.

For that, i thank you. 

Quote from: ninjeff on April 25, 2012, 12:56:47 PM
Sir, i have no idea what any of that meant, but i now have confidence that at least i shall not perish in a ball of purple fire on the way home.

For that, i thank you. 

If you don't hit any dogs.......


(too soon?)

I think cheetahman was considering the situation of flooding the engine, not starving it, and I am certainly not saying that you can starve the bike with the petcock on prime.  However, if the diaphragm in the petcock is messed up, then I do believe your bike could be fuel staved in the on or reserve position.  Also, you are trusting a piece of rubber with a spring and needle valves which can get stuck or slowly leak due to wear to keep your bike from flooding when it sits.  For both of these reasons, and because it was cheaper to get a non-vacuum replacement petcock, I went with a non-vacuum petcock. 

I'm not out here saying that vacuum petcocks don't work, or that all fuel stavation issues are due to the petcock. 

LOL adidasguy.

QuoteYea, plenty of gas in there. About 1/4 full, which should be fine on reserve. I would think.

You're probably out of gas, honestly. The sump in the tank is pretty high, and the tank doesn't need to be empty to be supplying insufficient fuel pressure to keep the bike running properly. When i start to see the most metal of the angly bottom of the fuel tank, it is empty enough to cause fuel pressure issues. Erratic idle, and sputtering included. It was that way especially before, when my petcock diaphragm was old and hard from disuse.

LMAO! (adidasguy)

Anyway, whats got me curious, is that it ran just great last week, before i put in the size 40 jets. Albeit it was running lean, but it would run none-the-less.

The size 40 jets corrected the lean issue, but now it seems like i can only keep it running with judicious use of the idle screw.

Also, it will start just fine. When it gets warm the issues creep up.

Quote from: adidasguy on April 25, 2012, 01:03:28 PM

Quote from: ninjeff on April 25, 2012, 12:56:47 PM
Sir, i have no idea what any of that meant, but i now have confidence that at least i shall not perish in a ball of purple fire on the way home.

For that, i thank you. 

If you don't hit any dogs.......


(too soon?)

But then he'll have a nice red 636.