Air-mixture screws were set differently at the factory

[Darkstar]

Thanks, with that in mind, these are my next steps:
1. Measure float height
2. Remove pilot mixture screws and inspect o-rings
3. Inspect slide and needle movement again
4. Tighten c clips
5. Test ride

[The Buddha]

if it has a vacuum leak you'd have issue idling...

my idle is fine, so that's one test checked off the list and a reason not to buy a cigar...much obliged. now if you tell me that i gotta pull the o-ring from the mixture screw threads, id use other words.    i'll put tube float level test at the top of my list.

Again will suck in air like a mofo if that O ring was bad and idle like crap and run great when revved.

And if you do pull it, I'd guarantee you, it will get shredded on the threads and spring on the way out and you will have to replace it. I'd correct the big issue first and do this, when its the only issue there is. Cos I'll guarantee you, you'd druck it up.

Cool.
Buddha.

[Darkstar]

I'd correct the big issue first

so to deduce:, i can take air leaks out of the equation because i idle well, and take jets out because it revs well at all RPMS's, and it's not likely the pilot circuit because it wouldn't idle if that was screwed up, but Im still running rich enough for enricher to stall, so this is why float height is the next right thing to check, is this the right line of thinking?

[The Buddha]

I'd correct the big issue first

so to deduce:, i can take air leaks out of the equation because i idle well, and take jets out because it revs well at all RPMS's, and it's not likely the pilot circuit because it wouldn't idle if that was screwed up, but Im still running rich enough for enricher to stall, so this is why float height is the next right thing to check, is this the right line of thinking?

That's my line of reasoning so far. Check first before you open and start doing things @ random - oh one more check.

A float that is too high will be low on power and be boggy and sneezy as you accelerate but run well on steady throttle especially in the 1/4 to 3/4 throttle range. Too low, and it will pull fine but, misfire like a shot gun but still have good power (odd feeling) and surge and lack power and be unable to hold rpm on steady throttle.

Check the level with U-tube. Easier than riding it. Fix that, then ride it looking for the other symptoms. You have to start with a known location.

Cool.
Buddha.

[Darkstar]

A float that is too high...

Bingo. I owe you...and everyone else here that helped...beer. They're both very high, but it's not the float tang setting causing it. I'll consider this thread closed now because we found the main problem. Here's a new thread I opened to address the underlying cause, in case someone else comes along with the same problem ----->  http://gstwins.com/gsboard/index.php?topic=71328.0

[Darkstar]

o-rings...I almost 100% guarantee you they are bad.

ok, i can do this job now. would you mind verifying the part? i think it's this:

http://www.bikebandit.com/oem-parts/detail/suzuki/13295-29900/b1047061?m=16095&sch=649433

shown as list item #17 in this diagram:
http://www.bikebandit.com/oem-parts/2007-suzuki-gs500f/o/m16095#sch649433

[mr72]

Yeah, 17

and also get 14 and the o-ring on the part labeled 21

or go here http://www.thisoldtractor.com/for_sale_dr350_orings.html and order :

2 ea of SPN# 09280-40010
2 ea of SPN# 13295-29900 (that's the part #17)
2 ea of SPN# 13374-35C00 (that's the o-ring on the #21)
2 ea of SPN# 13374-46710 (that's #14)


I haven't added it up but it should be under $10 including shipping for all of these. While you have the carbs off to do the 14/17/21 parts, go ahead and change the intake boot o-rings (big ones).

IMHO

[Darkstar]

thanks so much for referring to me that site, what a great resource for saving money!

[Darkstar]

go ahead and change the intake boot o-rings (big ones)

are you referring to "TUBE,OUTLET 13881-01D60"? 
line item 4 here: http://www.bikebandit.com/oem-parts/2007-suzuki-gs500f/o/m16095#sch649434

[mr72]

No, it's the SPN# 09280-40010 referred above

They go between the intake boots and the cylinder head.

You remove the airbox, then the carbs, then the intake boots (via two bolts each) and the o-rings are in a recess on the cylinder head side of the boots.

Most likely the old ones are flat and hard and you will think they are hard plastic. The new ones will be round profile and soft rubber and you'll immediately see why they needed to be replaced.

[Darkstar]

between the intake boots and the cylinder head

I see now, have to remove the intake pipe assembly first. Thanks. I'm glad I asked for your help.

[Darkstar]

...needle/screw o-ring...the o-ring eventually hardens and flattens but IF YOU NEVER MOVE THE ADJUSTMENT SCREW then the seal never breaks...they are very hard to remove. I used a .018" guitar string bent into a "L" shape on the end to "pick" them out. It took freakin' forever and I swear I aged a decade doing it. Oh yeah and I did this on TWO sets of carbs.

I just removed the pilot air mixture screws and the o-ring is attached along with a washer. I did not have to dig them out. Were you referring to the pilot jet? Or maybe it's that way on the older model, this is an 07. I don't see o-rings underneath the pilot jet, it's brass to brass. There are no o-rings listed as a part on bike-bandit, nor thisoldtractor. The smallest o-ring he sells is OR-9, which is for air-mixture.

[mr72]

I just removed the pilot air mixture screws and the o-ring is attached along with a washer. I did not have to dig them out.

You mean, the o-ring (rubber) is stuck to the washer (stainless steel)?

Were you referring to the pilot jet?

No, I was talking about the pilot mixture "screw" needle. It's the thing you turn 2.5 turns out to get the mixture set. You have to drill and remove a cap to access it. It faces downwards on the bottom of the carb. The pointy end goes up into the orifice that feeds the pilot jet, so it limits the amount of fuel that can flow to the pilot jet.

The smallest o-ring he sells is OR-9, which is for air-mixture.

That's the one.

Assembled it looks like this:


This picture shows the assembly with labels:


If I understand correctly, you removed this pilot screw/needle and the washer came out with the o-ring stuck to it, right? If so, just peel them apart and throw away the bad o-ring, count yourself lucky it came out, and put a new one in, be done with it.

Otherwise, did no o-ring come out? Because if that's the case, then the o-ring is still in there and you have to find a way to sort of claw it out. I used a piece of 22AWG wire bent into a "L" to pick them out. It's not trivial.

It's easy to become convinced that there is no o-ring in there because they are really kind of difficult to get out. But unless you actually removed one, it's there. Or, some previous owner removed it and didn't replace it.

It fits into a round recess in there so you can't even see it, even with the carb on the bench and upside down and you shining a light in the hole while looking with a magnifier.

[Darkstar]

OR-9, which is for air-mixture.

Yep, that was it. They both came out intact with the washer, and were in pretty good shape. I replaced them anyway.
And you were right, the underlying cause for some of my problems was the ring on the needle valve seat. It was totally packed with white fuel crud----->http://imgur.com/a/8OYjO. This is the reason that no matter how far I adjusted the float bowl tab, the fuel level was too high. In addition, fuel had collected and left a varnish on the brass seat itself. So I cleaned and replaced both. One other thing wat that I discovered that the needle can go on two different ways, and the clasp that hold it to the float behaves differently each way. One way opens quick and one opens smooth. I set them both to open smooth. Buttoned it all up and took it for a ride. Choke now works as designed. Float levels are in line with the gaskets. Doesn't bog down so I assume it's no longer rich, although I want to pull plugs next week. Will be interested to see what effect it has on fuel consumption. And you were also right about the intake booth o-ring, one of them was not only dried and flat, but leaking. Thanks for the help Mr72, Buddha, and whomever else walked me through this.