Another update...

So, I'm convinced that I wasn't setting the clutch release adjustment quite right...  But I was able to tinker with it and drive, tinker more and drive, and I figured out what the proper adjustment should actually be, and what the adjustment is actually doing.  I now can say for certain that I know how to adjust where the friction zone happens*, as well as the freeplay of the clutch cable.  After some adjustment, I was able to gain more power while accelerating, and I was starting to notice slipping at high speeds.  Now everything is adjusted so I can't feel slippage anymore, the clutch's friction zone is right around the middle of the clutch lever travel space, and the proper amount of freeplay is in the cable.

I'm also fairly sure that my clutch lever loosening problem was found too...apparently I forgot to re-lock the lock nut on the clutch cable at the clutch lever end...covered it up with the rubber without locking it down, and I never happened to see that as an issue...  It looks like my clutch release adjustment was indeed getting tightened enough after all.

After checking RPM's against what mister posted...  It seems that I'm right in line with some of it at least.  If I get up to ~40mph and shift up to 4th, I cruise at around 4k RPMs.  If I gain speed in 3rd first, and then shift to 4th at around 60mph, my RPMs settle in at around 6k, and I will still gain speed, albeit extremely slowly until the RPMs get to around 7.5k-8k when it seem to not have anymore power.

Taking off from 1st seems slightly sluggish until RPMs get up to about 4k or so, then it accelerates exactly like I would expect for the rest of 1st gear, 2nd gear, and all of 3rd gear.  It's once I get upwards around ~60mph that my power goes away.

I'm starting to believe that I'm getting the clutch issues resolved, and that there's simply another issue still lingering as well.  I'll pull the plugs and have a look at those again and try swapping them, etc. and blowing out the carbs (and related hoses, etc.) with compressed air, and I'll find some clear hose to check float height, and all of that fun stuff...then again, maybe it's now time to just resolve the electrical and get that problem behind me with certainty as well.

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*Your friction zone is what is adjusted by the clutch release adjustment screw.  The Haynes manual is unclear as to what resistance point to go to, as well as what that backing off 1/4 to 1/2 turn does.  With a little bit of testing, I think I've "cracked the code".  I'd love review by someone more knowledgeable, just to be sure I'm not misdirecting anyone (including myself), but if you are intimately familiar with your bike/clutch/etc, you probably won't care to read on...fair warning.

Here's what the Haynes manual essentially says:
When setting the clutch release adjustment screw (under the small panel secured by 2 screws right above the clutch lever), loosen the lock nut and loosen the screw several turns, then tighten until you feel some resistance, then back it off 1/4 to 1/2 turn and lock the lock nut.

Here's what extra information I found out:
When tightening the adjustment screw by hand, you can feel 2 points of resistance: 1 somewhat subtle point when the screw first makes contact with the push rod, and 1 much less subtle point when the screw starts to tighten the push rod into the clutch.  I tried first by setting the screw at point 1 (the subtle resistance point) and I found that I had to pull the clutch lever almost all of the way to the handlebars to find my friction zone.  I then brought it back home, and set the screw at the 2nd point (the far less subtle point of resistance) and went out riding again.  This time, I found that my friction zone was almost immediately after the clutch lever's freeplay was out.

My personally updated guidelines of how to set this screw, based on all of the above:

• Loosen the lock nut
• Loosen the adjuster screw several turns, to be sure it is absolutely not in contact with the push rod
• Slowly tighten the adjustment screw by hand, until the slightest amount of resistance is felt -- Mark this as Position 1
• Continue to tighten the adjustment screw until very obvious resistance is felt -- Mark this as Position 2
• The distance between point 1 and point 2 might be roughly 3/4 of a full turn of the screw -- this distance is analogous to your clutch's friction zone.  Right in the middle of position 1 and position 2 should require the clutch to be pulled in about 1/2 way.  Going closer to position 1 moves the friction zone to your handlebars (requiring more applied force), and going closer to position 2 moves the friction zone away from your handlebars (requiring less applied force)
• Set the clutch release adjustment screw to your approximate preferred location, based on the above
• Hold the adjustment screw in place as you lock the lock nut into position, making sure to tighten appropriately
• Adjust the freeplay in the clutch cable as you normally would -- Since you're here with your tools, I'd recommend to adjust the cable at the handlebars to have the maximum amount of slack, and then adjust the freeplay at the clutch end of the cable. (This is actually the Haynes manual suggestion, but it makes sense, I think!)
• Make sure to lock the lock nuts at the handlebars and the clutch sides of the cable -- failure to do so will make your clutch lever go "squishy" while riding!

Another update...

Good news and bad news...bad first...

Stranded at the moment, waiting on a jump start.  It appears that my brand new battery isn't getting charged like it should.  I'll know for sure once some jumper cables arrive...

Good news though, is right before this ride I decided to go through and recheck everything I had been messing with, especially related to the clutch, and I found that the clutch cable was actually backed out of the engine case...it seems THAT was the real cause of my clutch cable loosening, etc.

Correcting that seemed to somewhat resolve (or at least once again improve) the situation.  I'll know a little better once I can get it on the freeway though.

Well, I just limped it home...  It wasn't the battery after all, though I'm not sure why the starter wasn't turning over at all when I first died.

So, I was driving along, then I started to get jerking motions before it just died when coming up to a stop (once I pulled the clutch all of the way in for longer than about 2 seconds).  I restarted it, got part way down the next street and it started doing the same thing, so I flipped my petcock to reserve (even though I've only gone 83 miles since I last filled up), and as I expected it didn't change anything really.

Shortly after that, it died on me, and I couldn't get any activity out of the starter.  The first time I tried while I was still moving; clutch pulled in, still going about 35mph, starter doesn't even turn over (everything is just silent).  Since I still had momentum, I was able to coast into a parking lot.  I again tried to start the bike, but there was nothing from the starter.  The oil light was on, the head/tail lights were on (I still haven't fixed my neutral light though...shame on me ...), but no activity from the starter.

It turned out, the parking lot was a slight slope, so I tried to push start it -- no luck.  At this point, I pulled into some shade, tried the starter one more time and then made the previous post.

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After waiting a little bit and checking over everything for any obvious signs of trouble but I don't see anything in particular, so I just decided to browse the forums while I waited...quickly got tired of the heat, and so I decided to try it again.

Amazingly enough, the starter was turning over again and after a little coaxing, I was able to get it started and out on the road again towards home.  However, on the very next block, I started to hear some backfiring and it ended up dying right as I pulled up to the next light...  The better news this time, was the starter was still trying its damnedest, but it just couldn't get the engine started.

I limped it home like that...having it die, me working on getting it started via push starts and/or using the starter and crossing my fingers.  It basically died at every intersection where I had to come to a full stop and had the same issue, and even while riding, it was a rough ride with backfiring...


I'm going to pull my plugs right now and check on them...  But in the mean time, is there anything obvious that this behavior would suggest?

Plugs looked to be in exactly the same condition as when I last checked.  It still won't really get going, though now it seems to try every time.  Seems pretty fishy that it happened right after getting the clutch to a point where I felt like it was possibly "normal"...  It makes me wonder if getting the clutch fixed is making my old, original problem come back...and maybe it wasn't even loose plugs after all.

I'm starting to suspect electrical on the bike enough that I've scheduled tomorrow to just check over all of the electrical on the bike.  Will report back once that's done.

To check the operation of your carb slides, fire the bike up with the filter/airbox off (make sure there's nothing loose nearby and it's not really dusty, naturally) and rev it a bit, looking into the filter sides of the carbs. You should see the slides move at least a tad bit up and down, and they should move equal amounts (but not synchronously). More airflow should mean the slides go higher. Be careful not to over rev or overheat the engine.

As far as the clutch adjustment goes, at least on my '91 - I haven't bothered getting at the adjustment on the side of the sprocket cover, but there's an adjuster/locknut on top of the sprocket cover (cable passes through it) as well as one with a thumb nut under the rubber cover near the lever. So long as the clutch lever has wiggle room (maybe half an inch or more at the tip) between being all the way out and where you feel it actually pulling on the clutch you should be fine so long as your clutch doesn't drag when you have the lever all the way in. Anywhere in between is a matter of preference, although someone will probably come along and quote factory specs.

With bike sputtering and dieing, since you mentioned replacing the fuel lines check your routing. Make sure that the lines aren't too long or sitting up against parts of the engine, you may be boiling off your fuel in the lines. Also, double check that there aren't any kinks. If you experience the problem again, first pop your gas cap, let it sit for a couple seconds on prime, and see if it will start again. If not, close the gas cap and let the bike sit for 10 minutes or so to cool down and see if it will work then. While you wait, pull a plug boot, put a piece of metal in the boot, and bring the metal close to the engine or frame and crank it with the starter to test for spark.

On the starter not working - It may be something to do with the clutch safety switch since your clutch was out of whack before. I've also had the odd, rare instance of my starter not working, but as soon as I turned the engine a bit by pushing the bike a few inches it's worked fine -- you may have done this trying to push start it.

Badot:
Checking the carb slides will be on my list of things to do tomorrow.  Thanks for the info on that.

I was making adjustments in all 3 clutch adjustment places.  The adjustment at the engine case was the one that was unscrewed completely.  It was still held in place firmly because of the cable...what finally tipped me off to there even being a problem was when I made another minor adjustment to it and the lock nut didn't tighten...it just pulled the thing out instead.  Whoops.  I honestly don't know how long that was like that, but it was probably from when I first adjusted the thing.

You mention the fuel lines...  Funny that I was thinking about that too.  After looking at many posts here, it looks like I may very well have my hoses backwards.  I got the routing from the Suzuki parts diagram blowouts, but posts here disagree with that -- I'm more inclined to believe you guys at this point too.  From another post, I found that the tank petcock has an 'R' at least, and possibly an 'O' to help...I was going to hope to see these marks on the main petcock and match that way.

Also, when I looked in the tank a little earlier (because a visual inspection is always good), it looked like the fuel level might low enough that I might be right at the on/reserve cut-off point too.  There's obviously fuel in it, but as others have said, that can be misleading.  I'm also going to go grab some fuel to be sure.  My trip meter has ~90 miles since I last filled it, so I would have guessed to have a few more miles at least before hitting that point, but that could be all it is...this symptom does seem easily fuel-related.

The electrical is also a potential issue, since previous owners did add aftermarket lights, etc.  I'm just going to trace everything and make sure I can rule that out as a possibility too.  I didn't even know there was a clutch safety switch.   I guess I'll probably have to come across that switch at some point tomorrow though.


Thanks for the info...lots of that helps!  Testing procedures like that are the things I need to learn most.

Just verified...  Both the tank petcock and the main petcock are labeled.  There is no reason for anyone to mix this up...just look at the labels.  I was "blindly following orders" from the Haynes manual and it wasn't clear enough, so I pulled my info from the Suzuki parts diagram, thinking that had to be right...  It would have been far better to just look where the hoses connect.

My sputtering felt like it easily could have been gas, and this probably solidifies that as the issue I had yesterday.

I noticed this as I was gearing up to check over the electrical...still going to do that to be sure of the other questionables (like my neutral switch/light situation and the previous owners' work), but with finding that clutch adjuster totally out of place and the reversed fuel hoses...  I may have a perfectly fine bike when I'm through today!

I'll report back either way and let you guys know.  Either way, thanks again everyone for the help/suggestions/ideas/etc.  I think this problem forced me to essentially take a crash course on nearly every major system on the bike, and I'm far more confident in tackling stuff like this.  You guys kick ass.

Another update.

The electrical seems to check out.  The neutral light issue was the bulb after all.  Everything else seems to be working properly.

Reversing my fuel hoses (and adding fuel to the tank, since reversed fuel hoses result in "prematurely" empty tanks) completely resolved my issue of being stranded the other day...it was just gas after all, and my attempts at push starting it while limping it home probably let just enough fuel trickle into the lines so that I could start it and go for just a little bit before it would die again.

My clutch does not seem to be coming loose anymore, and the operation stays consistent throughout my ride now.  I don't feel any obvious slipping, and engine breaking works wonderfully.

The good news about the above, is that when I was running out of gas, it immediately felt to me like running out of gas might be my issue.  The bad news, is that is definitely not the same issue that it all started with, and it's absolutely not the problem I'm still having.

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Now, it feels like taking off from first is perhaps slightly more rough than it should be, until the bike makes it up to around 4k RPMs.  If I'm really easy on the clutch, it won't chug on take-off, but there's not much power until the 4k RPM mark or so.  After that point, it seems to have decent power for all of 2nd and 3rd gear.  4th-6th are fine so long as my speed is below ~60mph.

On the freeway, I can get up to ~80mph in 3rd gear, but the moment I shift to 4th, it looses power and slowly decelerates (even with full throttle) until it drops down to about 60-65mph...all of this on level ground.  I can maintain speed and accelerate past traffic (and even slowly accelerate up minor hills) in 3rd, but it takes some time...and once I go above 3rd gear it's like the engine simply struggles to continue to output.

When I am riding at full throttle, I can slowly roll the throttle back until about 1/2 throttle before the engine starts to sound different and the bike actually starts to slow down.  This effect is extremely obvious in 4th-6th at freeway speeds.

For these symptoms, the Haynes manual seems to point primarily at the carburetors...so I'll probably turn today into another carb day.  Going to check the slides, blow out the passages with compressed air, remove the hoses and blow all of them out as well, check float height, etc.

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Here's the big question now...  How fast should the bike accelerate, and what should my effective top speeds be in various conditions?

My major comparison is with my Toyota Corolla...and right now, I seem to be able to accelerate at about the same effective speed from 0-50 as my Corolla.  I would assume that the bike should be a bit snappier than my car, but that isn't the case.  If I were to drag race myself, side by side, I would probably still win in my Corolla though...  I'm really not certain, but this seems wrong.  Perhaps not nearly as wrong as I might think, but it seems like the GS500 should be able to perform better than that (I feel like it did when I first got it, though I didn't really truly pay quite as much attention as now).

Top speeds?

Ok, go read my message elsewhere in this thread about RPMs http://gstwins.com/gsboard/index.php?topic=61400.msg714164#msg714164

If your RPMs can match those you have something to work with. If not, there is something to work On. Double check then get back to us with the results.

Michael

Mister:
My RPMs seem to be in-line with that.  I can't check 6th gear for certain though, since I can't maintain speed at that gear, but for 4th, I can say that I match.

It really feels like the engine just stops delivering any more power, and there is a shift in tone at the same time my throttle stops being effective (this is the sound that makes me feel like it could possibly be the air filter or something).  It's almost as if the engine knew it needed to deliver more, but it simply couldn't do any better than it was at.  The thing that draws me to the carburetors though is that it seems linked to throttle position rather than road speed.

Before taking the carbs off my bike, I checked the float height with clear tube method...and I found that only the carb on the right side was off...fuel is coming up above the gasket (about 1/4" or maybe a little less).  Could something like this be the cause of my issues?  What would happen if just one float were off by about that much?

I also noticed this time that a vacuum seal is cracked and should probably be replaced.  If we add this into the mix with the find above, would that all add up to the issue?


Now, the big one this time...  How do I adjust the float height correctly on a 2005 model?  My carburetor is simply different than the one in the Haynes manual, and while I think I could probably figure something out, I'd rather be certain I was doing it the right way.  Can anyone point me to how to adjust the height on a 2005 model specifically?

Oh, and one of my throttle cables stabbed my finger when I took them off of the carbs.  I'm going to need to replace that thing for sure too.  It's starting to fray somewhat near the ball-end that hooks onto the carbs.  Significant, but probably not something that I would have really noticed until it would seem to stretch, right?

Hopefully the local shop has something that will fit my bike for this one...seems like it would probably be rather generic though.

If the carb height is too high, you'll get fuel draining into the crankcase, which is never good. Surely a vacuum leak could be contributing to your issues.

The Haynes manual I have includes pictures of the early model carbs and the late model carbs at the beginning of the chapter. Though the float height adjustment process is illustrated using pictures of the old carbs, the process is the same for the newer kind.

I just wanted to be sure I was bending the right part.  The tab on my floats looks very different from what's pictured.  I think I've got that figured out.  We'll see in a little bit...gonna run and get some parts.

You mention little power in first gear till 4k rpms... I don't think that's out of the norm for these bikes. In most gears, under 3.5 k rpms and you will definitely feel the engine chugging with no immediate acceleration when you put on the throttle.  It's harder on the bike to do that, so try to get the revs up before really loading any decent amount of throttle... A quick downshift may help if you are in a higher gear.

-Bboy

BockinBboy:
Good to know.  I figured it probably was, but I just wanted to be sure that was normal for certain.  I've been noticing that my best power range is between around 6k RPMs and 8.5k RPMs.  I try to set myself in a gear so that I am sitting around 6k RPMs as I cruise along, so I can quickly get some speed if needed.  For my speed tests, I was still finding power at high speed when I dropped to 3rd, but 4th and above just couldn't cut it.  Even at full throttle in 4th gear...so if I change to 4th at 80mph, I would start to slow down as if I had let off the throttle a bit.  It would rather quickly (well within a 1/4 of a mile) slow down to around 65, but I could drop into 3rd and accelerate again.

Hopefully that float on the right carb being adjusted to the right height and replacing that vacuum cap will make all the difference with my throttle/power.  It's just too bad I had to deem it unfit to ride until a new throttle cable arrives though.

Well, after a nice long wait on a back ordered throttle cable, I was able to get everything back together for a test drive again.

Here's what I did to it this round:

• I put a brand new air filter in it.
• I adjusted the float height on the carbs after noticing one side off a bit.
• I re-capped a vacuum seal on the carburetor since the rubber was cracked all of the way through.

After my test drive, I have good news and bad news:

• The good news is that starting out of first seems a bit smoother than it was before, but it's still probably not at 100% yet.
• The bad news is that my top speed/throttle issue hasn't gone away.....though usually only seen in higher gears, if I accelerate quickly out of first it can suffer from the throttle issue too.

When in 3rd or greater is when I notice the 1/2 throttle issue the most; between full throttle and 1/2 seems to be no change in power.  It also still seems to have the same "air sucking" sound when I apply more than 1/2 throttle...  It sounds as if it were trying to pull more air through and it wasn't getting through for some reason...something like that (it really reminds me of what my car sounds like when its air filter gets pretty dirty).  4th gear has nearly 0 acceleration, 5th gear can simply maintain speeds lower than ~60-65mph, and I haven't even really bothered with 6th, assuming it would be the same too.

I'm out of ideas again for the moment...

have you checked to see if the carburetor butterflys are opening fully and in unision .You will need to remove slides to see, unless you have carbs removed from there boots and can see and operate the throttle.

Sorry Nicro, I can't remember what you have / have not done entirely. But it's sounding like a high rpm fuel delivery issue. Float bowl level, constricting petcock(s), clogged gas cap vent, clogged carb vents, or a dirty inline fuel filter (on tank petcock or aftermarket).

Alright...so, I eventually gave in and took my bike to the shop.  After all of the waiting, I'm finally back in action using my GS as a daily driver.

It turns out, the guy I bought the bike from had the wrong size pilot and main gets in the carbs.  I'm not sure if it was working great when I got it just on chance, or if I just hadn't driven it hard enough to really know...but apparently when I started fixing things, it looks like I might have "fixed" enough that it threw the whole system out of whack.  The jets that were on the bike were making the mix too rich, and there was just no way around it I guess.

I just wanted to update the thread with some closure, and say thanks again for all of the help from everyone.  I learned plenty about my bike in the process, and now my daily commute is much more entertaining.  Hopefully this beast of a thread can still help others that wander through on a search!