Removed the filter today and found a couple cm of oil and fuel at the bottom of the air box sitting there.. Any idea what could cause this?

The fuel I'm not so sure about unless you're getting excessive backfiring inside the carb intake. The most likely thing is that the oil blew in there from the vent line that goes from the top of the valve cover to the box. I forgot what it's called but it's some kind of emission control crap. It's possible that you are mistaking the smell of used oil for gas since engine oil, especially on these bikes, usually gets contaminated with fuel. There could be some water in there as well that's adding to the mixture.

I'm not a Suzuki mechanic but I've had my tank/airbox/carbs off enough times to see that there is really no way for any substantial amount fuel to get into the airbox unless you have a leak in your tank, which you would know about. I'd double check but unless you're smelling gas while the bike is just sitting, chances are high that you don't have a leak.

Edit: Oh! Epiphany here...check to make sure the vent line on the bottom of the tank is securely installed. It could be that it fell off and when you fill the bike the gas is spilling down on top of the box and getting in.

I've been thinking this over and it occurred to me it's possible your float needle(s) is/are sticking and causing fuel to flow up into the box/engine. Though you'd think this would almost certainly cause the bike to run poorly, if at all, it is something to check on. Just make sure that when you pull the carbs loose that there isn't a bunch of fuel all over the throat(s). If there is...um, well, the next project on your list is going be a carb rebuild. Sorry!

Sold the GS this morning! Thanks for the attempted help (i passed it along to the new owner). Hopefully He has the time to take care of PITA that i didn't have anymore

No problem man. I wouldn't worry too much about it.

Quote from: numus on December 26, 2011, 01:43:11 PM
Sold the GS this morning! Thanks for the attempted help (i passed it along to the new owner). Hopefully He has the time to take care of PITA that i didn't have anymore

Does the new owner know of this problem - or - did you hide it from them so we will end up seeing them here asking about it, then watch them get all annoyed when they discover you were here first and knowingly sold them the bike without mentioning this problem?

Michael

As the new owner of this bike, I have to say, yes, numus was quite honest with the issues it has.  It appears he has done quite a bit of work on it, and I'm getting closer to having it running again.

Since I purchased the bike, I've done the following:  Replaced fuel filters and fuel lines, and cleaned the carbs.  It is no longer pouring fuel into the airbox.  However, it still has the same problems:

Will idle, but dies after a couple of minutes.   Sometimes it will restart immediately, others it takes a few minutes. 

While idling, if you slowly give the bike throttle, it will rev to about 4500/5000 rpm prior to dying.  If you quickly rev the throttle, it dies almost immediately.

I have ordered new spark plugs, but I'm not sure that will help any.  The bike will start with the left plug in, right plug unplugged, but will not start with the right plug in, left plug unplugged.  I've tried swapping the plugs, and the issue remained the same.  Coils, maybe?

Any ideas?  I've been working steadily at it for the past 3 days, and am not making the kind of progress I'd hoped.



And since I'm new here, I didn't want to start a new post, although I would like to so that I can get more replies to my issues.

I had similar symptoms with Trey. However, when I swapped the plugs the problem switched to the other cylinder. So it was  the plug. Off thing was it would run with full choke with just the bad plug which made me thing at first it was not a plug. It was a flaky plug - not good and not totally bad.

.......before swapping plugs.....
I replaced coils and ignitor box with no effect.

I did poor-man's compression test by cranking engine with thumb over plug hole and all was OK (later bought compression tester just to be sure).

Cleaned and adjusted carbs.
...................

Given what I did to get Trey running and your symptoms, I'd check for spark. Pull the plug and hold against engine frame. Is there visible spark? If not, probably coil. Could be wiring to coil or bad connection on ignitor box.

You might verify the setting of the mixture screws (if they are accessible. If not, then they are still factory set which is OK).

One other thing might be carb syncing. If you have spark, will it run on the bad side at all? What about full and no choke? If either, then sync the carbs. I did a post on the hillbilly method of carb syncing. It worked really well.

First of all, thank you for the response.

Pulled the plug and held it against the frame, got nice strong spark.

I'm not certain if the mixture screws are accessible, because I didn't want to foul anything up terribly when I cleaned the carbs, so I only removed the main components.  The float bowl covers were quite dirty, but the bowls themselves weren't terrible.  Although, one was worse than the other, trying to remember if it was the right one (I want to say it was).  One of the main jets was completely clogged, the other not.  I'm guessing I just need to strip them apart again and see if there is an obstruction.

I tried starting the bike with only the right plug at full choke/no choke, various throttle positions with no luck.  It simply will not start.  The bike will start with the left plug or both plugs, however if I unplug the right plug while the bike is running it has absolutely no effect. 

I also started the bike with the right plug completely removed and had strong air bursts coming from the cylinder, so I assume compression is good?


Also, while I'm thinking about it, I checked the floats to see if they were getting fuel, and the left one is fine.  The right one, however, has a stripped screw, so I've been unable to check it.  And tips for removing this screw, short of the taking the carbs off and taking a dremel to it?

What year is the bike? I don't thing that was mentioned anywhere.

Sounds like clogged up carb since you have spark. If the plug was wet, then maybe flooding and too much fuel.
If you haven't, use carb cleaner and clean all openings really good and blow air through them. Especially the openings in the air intake side. Put in new jets just to be sure they're clean. A few places can get them to you overnight (like PJ Motorsports). Some people have extra jets but we need to know what year the bike is.

Check for gas in the carbs. Connect a cleat tube to the drain on each side. Bend the tube up higher than the carbs. Then open the drain screw. You'll see the fuel level in the tubes. That will tell you if needles are stuck open, closed or are working right. There are topics on adjusting float levels as well as in the Haynes or Clymer manuals.

PS: If the screw is stripped, you gotta be able to remove it. How else can you clean the carbs if you don't drain them first? (unless you want a quarter cup of gas to spill out when you take the bottoms off).

Stripped screw is a sign someone has really been messing with the carbs and didn't know what they were doing. Pretty easy to open the drain. I recall my carbs had drain screws that were hex head with slot and phillips so 3 ways to open it up. As for the float bowl screws (2 on older, 4 on newer) if stripped, many threads on this topic. Vice grips or dremel. Replace with stainless steel hex key screws or at least good quality new screws.

PSPS: You might want to invest in a spare set of carbs. $75-$150. Buy ones from a running bike and from a reputable seller. I have a few spare sets - some were pretty cheap. I threw on a spare set on Trey as a test to see if my carbs were all farkled. He ran the same with the spare set so his problem wasn't the carbs - though a cleaning of the carbs did make an improvement once I determined it was a flaky plug.

It's a 96.  My next step was to check the float height, but as I said, the screw on the right float bowl cover is stripped, so I've got to sort that issue out.  Guess I'll head back out and pull the carbs again.


I may just take your advise and buy some new/used carbs.  Any suggestions on a good seller?

Quote from: shonole on December 28, 2011, 12:34:07 PMOne of the main jets was completely clogged, the other not.

If you had a plugged main, I would really wonder about the status of the pilots, cause they are 5X more likely to clog than a main?

I'm going to take a look at it now and see about cleaning them. 

I bought Phenix's frame and some other parts from here. Looks like these carbs are from that same bike. Frame was expertly repainted, so I would think the carbs were well taken care of, too
http://www.ebay.com/itm/Suzuki-GS-500-Carburetors-/170655128818?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item27bbd69cf2

Seems to be the best deal right now.

PS: Drain screws are special, so just any screw won't work. I gave away drain screws from a junk set I had. Someone might have a junk set and give/sell you the drain screws.
You have old carbs. I got 4 pilots and 4 mains from Bike Bandit. They were so slow shipping I bought ones from PJ while waiting for BB's to show up.  So I do have extra jets in the parts bins. Only one spare set of old carbs - which I need to keep - sorry. It would be possible to overnight them tomorrow if you want to work this weekend and pay the express mail postage.

(note: at BB: "In Stock" does not mean on the shelf and can ship right away. It means "we can get it someday then ship to you")

PM me cost and I'll get back to you.

Thanks!

Also, I'm hunting for a rebuild kit (I believe I've narrowed the problem down to the float needle.  In fact, I think both of them are shot).  Will the one listed here work?

http://www.partsnmore.com/parts/suzuki/gs500/?filters%5Bfitting%5D=custom

It is listed for 89-93, but should work on the 96, right?  If not, I'll just order the float needles, as the gaskets look okay.

This is for 89-00 so I suspect any one in that range would work - carbs did not change
http://www.oldbikebarn.com/Suzuki-GS500-GSX1000-Carb-Repair-Kit?sc=2&category=126
I have kits but  paid $24 from BB and now they are at $30.56 from them.
This place is $22
http://www.powersportsuperstore.com/K-L-Supply-Carburetor-Repair-Kit-18-9310-p/4070325.htm?Click=35177

If they are selling the K&L, it will work 89-00. Then any should as 89-00 are the same carbs.

Jets would be $11 for 2 each 122.5 mains and 40 pilots. USA used 37's, rest of world 40's. I prefer the 40's as Junior had them (Canadian) and starts better with less choke, better power at low rpm's.

Express mail is $18.30.

Okay, I'll get back with you shortly.

The pilots appear to be stuck, and I'm deathly afraid of stripping them.  Any tips?  Or am I just screwed?

I'd let someone else say what to do there. I've only removed them from a couple sets and they were easy. I haven't encountered a stuck one.

My first guess would be to heat outside with a hair dryer. The heat can expand the housing and free the jets. PB Blaster or the SeaFoam bolt free-er stuff could help.

Seems that carb is really gunky. Probably the internal passages are fouled, too. You'd need the K&L Carb cleaning tool (sets of small, rough wires for the holes) maybe. If the jets can't be removed, I'd opt for another set of carbs.

Well, I've got them soaking in pb blaster overnight, so we'll see how it is in the morning.

Shonole check the RH coil wire.... Trace it back to above the starter solenoid and desolder the additional wire on that. That is the electronic Tach.. It should not be causing a massive voltage drop to the RH coil to cause a problem (but it may be).

I never took apart the carbs but according to the owner before me, he took it to http://www.floridamotorsports.com/ and had them work on the carb... They usually are really good but they may have stripped it... MY suggestion (since it was what i was doing when i was working on rebuilding the bike) everytime you remove a bolt, go to ace hardware and get a chrome replacement (usually grade 8 i believe).. Thats why you will notice some nice new shiny bolts randomly...


BTW I did do an entire check on the regulator/rectifier and the generator. Everything appeared within the manual specs but i did replace the 3 sets of disconnects on the generator (left side behind left fairing). It was having a random disconnect at those points so i figured to replace the entire thing. The power system (out of the generator and rectifier) shows a good charge voltage...
Just trying to help narrow down that I don't believe it has anything to do with the power system (although you may have a random ground somewhere.. although the symptoms didnt really support that)

Quote from: mister on December 26, 2011, 06:23:17 PM

Quote from: numus on December 26, 2011, 01:43:11 PM
Sold the GS this morning! Thanks for the attempted help (i passed it along to the new owner). Hopefully He has the time to take care of PITA that i didn't have anymore

Does the new owner know of this problem - or - did you hide it from them so we will end up seeing them here asking about it, then watch them get all annoyed when they discover you were here first and knowingly sold them the bike without mentioning this problem?

Michael

I would never do that to someone (because i would hope no one would ever do that to me)...
Trust me.. for the price I sold the bike at, it is worth well more than that in parts alone...

Quote from: shonole on December 28, 2011, 03:34:48 PM
PM me cost and I'll get back to you.

Thanks!

Also, I'm hunting for a rebuild kit (I believe I've narrowed the problem down to the float needle.  In fact, I think both of them are shot).  Will the one listed here work?

http://www.partsnmore.com/parts/suzuki/gs500/?filters%5Bfitting%5D=custom

It is listed for 89-93, but should work on the 96, right?  If not, I'll just order the float needles, as the gaskets look okay.

I believe between 89 and 00 nothing with the engine or carbs was changed... Someone correct me if I am wrong.


Another thing i would advise you to do is to pull the kill switch for now and wire in a temporary one... That showed signs of possibly having problems and would be easier to narrow down if there is any problems in the electrical system.


P.S. I totally forgot to mention this when you bought it... The brake switch for the rear brake did break...
http://www.ebay.com/itm/suzuki-1991-GS500E-brake-switch-/130530477359?item=130530477359&vxp=mtr#ht_500wt_1127 is a replacement but I would advise getting the one that replaces the bolt... Should look something like this http://www.bonanza.com/listings/Motorcycle-banjo-brake-switch-bolt-dual-sport-dirt-bike-ktm/38349712 ... It isn't critical as long as you always use the front brake along with the rear brake (the front brake will activate the brake lights)...


I keep getting other random thoughts and coming back to this post to add them:

Another thing to look at is the fuel overflow line was never installed on the bike (this occurred sometime before I bought the bike) and it is possible that excess fuel dumped into the air box because the port sits right above it i believe... Make sure to add a new line that dumps out the bottom of the bike.