WTF??? I \bought this bike a few months back as a winter project/commuter bike.
2001 GS 500, bone stock, 15,000 miles on it. P/O said it had sat for a year and would not start. He bought a service manual and tried to clean the carbs but still could not get her started. I picked it up for a great price and brought it home. Pulled the carbs and soaked/cleaned them really good. put her back together and it wouldn't start. Noticed that I was getting a lot of fule dumping from the back of the carbs into the airbox and eventually out of the airbox overflow. I ordered a new set of needle valves / needle valve seats figuring that it was the problem. Got around to putting the new stuff in and I still have alot of fuel coming into the airbox from the carbs, the plugs are both sopping wet with fuel, but there is plenty of spark. I rechecked the float heights and they are as follows: left - 12.99-13.54mm / right - 12.69-13.09mm.
When I 1st put it all back together, I had the petcock on prime, choke on....it started for about 2 seconds with a low (800 rpm's) idle and then stalled, turned the petcock to on and then she wouldn't restart at all and I noticed the fuel dump (it's dumping around 4-6 ounces out of the airbox overflow with 3-5 minutes of cranking). I assume that the issue is too much fuel, but I have rechecked and double checked the floats/needle valve/seats. What should my next course of action be? Is it possibly an issue with either of the two petcocks?
Also, can anyone tell me if I can put a new (TPS model) set of carbs from a GS 500F on this bike and just leave the TPS unplugged? Would that work? I have heard of doing this with dirt bikes, so I assume it should work with this right?
Also, is it possible that the P/O "hollowed" out the jets when he attempted to clean them?, and now they are much bigger?
Any help/suggestions are welcome :thumb:
BTW, looks like stock jetting from what I can make out on the jets (127 something on the mains, 17.5 on the pilots, and a "6 something" on the mids...)
One thing to also check.
look down the intake and exhaust tubes on the motor.
check to see if you see any light when the valves are supposed to be Closed.
Shine a flashlight down the spark plug hole while looking down the tubes.
if you see light, theres your problem
if they are not closed FULLY, it wont start.
Just got a new head for my bike and the intake valves were not closing.
Just took them out and it was gunked up pretty good.
no idea if this will help, but it is a possible problem to check.
Quote from: craigs449 on January 28, 2012, 12:58:56 PM
WTF??? I \bought this bike a few months back as a winter project/commuter bike.
2001 GS 500, bone stock, 15,000 miles on it. P/O said it had sat for a year and would not start. He bought a service manual and tried to clean the carbs but still could not get her started. I picked it up for a great price and brought it home. Pulled the carbs and soaked/cleaned them really good. put her back together and it wouldn't start. Noticed that I was getting a lot of fule dumping from the back of the carbs into the airbox and eventually out of the airbox overflow. I ordered a new set of needle valves / needle valve seats figuring that it was the problem. Got around to putting the new stuff in and I still have alot of fuel coming into the airbox from the carbs, the plugs are both sopping wet with fuel, but there is plenty of spark. I rechecked the float heights and they are as follows: left - 12.99-13.54mm / right - 12.69-13.09mm.
When I 1st put it all back together, I had the petcock on prime, choke on....it started for about 2 seconds with a low (800 rpm's) idle and then stalled, turned the petcock to on and then she wouldn't restart at all and I noticed the fuel dump (it's dumping around 4-6 ounces out of the airbox overflow with 3-5 minutes of cranking). I assume that the issue is too much fuel, but I have rechecked and double checked the floats/needle valve/seats. What should my next course of action be? Is it possibly an issue with either of the two petcocks?
Also, can anyone tell me if I can put a new (TPS model) set of carbs from a GS 500F on this bike and just leave the TPS unplugged? Would that work? I have heard of doing this with dirt bikes, so I assume it should work with this right?
Also, is it possible that the P/O "hollowed" out the jets when he attempted to clean them?, and now they are much bigger?
Any help/suggestions are welcome :thumb:
BTW, looks like stock jetting from what I can make out on the jets (127 something on the mains, 17.5 on the pilots, and a "6 something" on the mids...)
I would check the petcocks before anything else. Start from the top and work your way down.
Check out my thread for some other replies:
http://gstwins.com/gsboard/index.php?topic=58643.0
Where is your fuel? Do you have the tank on or are you using a spare test bottle of fuel?
Fuel is gravity fed. If your fuel bottle is much higher than your tank would be, too much force of gravity and the floats can't stop the fuel from entering the carbs and it squirts out the carb air intakes. How do I know? Been there. Done it.
Lowered fuel bottle to no more than 1 foot above carbs and all was OK for testing.
Check the float height using the tube method: http://gstwin.com/float_height_check.htm
Flooding usually doesn't happen unless there's an issue with the float height. Since you said you put in brand new needles and seats, you can count that out as a potential issue. Even if the p/o did hollow the jets out, it would probably still run.
To check the petcock, put it on "ON" and disconnect from the carburetor. Fuel should NOT be coming out in a steady stream unless the bike is RUNNING. The petcock is operated by the vacuum line attached to the carburetor, so unless the bike is running (or being started), no fuel should come out (except what's left in the line after you disconnect it).
A free-flowing petcock would not cause the issues you are describing, many people replace theirs with regular on/off/reserve petcocks and are fine.
List of other potential issues:
-Floats sticking open causing fuel to be dumped into the carb and subsequently the motor and airbox.
-Carburetor vent line clogged
-Diaphragm/needle improperly installed causing fuel to be sucked up through the main jet and into the venturi when no throttle is being applied.
-Idle speed set incorrectly
I got a K&L carb rebuild kit when I rebuilt my carbs. I had the issue of fuel coming out the air jets to the airbox side too. Then I took out the needle valve and compared it to the one I had replaced. I realized that the new needle valve was actually shorter than the original. This was causing it not to close properly despite proper float height. Check yours and see if you have the same issue.
Also, those float heights are slightly low. I believe my manual said 14mm +-1 mm. I could be wrong, I don't have it in front of me.
Quote from: shonole on January 28, 2012, 01:12:10 PM
Quote from: craigs449 on January 28, 2012, 12:58:56 PM
WTF??? I \bought this bike a few months back as a winter project/commuter bike.
2001 GS 500, bone stock, 15,000 miles on it. P/O said it had sat for a year and would not start. He bought a service manual and tried to clean the carbs but still could not get her started. I picked it up for a great price and brought it home. Pulled the carbs and soaked/cleaned them really good. put her back together and it wouldn't start. Noticed that I was getting a lot of fule dumping from the back of the carbs into the airbox and eventually out of the airbox overflow. I ordered a new set of needle valves / needle valve seats figuring that it was the problem. Got around to putting the new stuff in and I still have alot of fuel coming into the airbox from the carbs, the plugs are both sopping wet with fuel, but there is plenty of spark. I rechecked the float heights and they are as follows: left - 12.99-13.54mm / right - 12.69-13.09mm.
When I 1st put it all back together, I had the petcock on prime, choke on....it started for about 2 seconds with a low (800 rpm's) idle and then stalled, turned the petcock to on and then she wouldn't restart at all and I noticed the fuel dump (it's dumping around 4-6 ounces out of the airbox overflow with 3-5 minutes of cranking). I assume that the issue is too much fuel, but I have rechecked and double checked the floats/needle valve/seats. What should my next course of action be? Is it possibly an issue with either of the two petcocks?
Also, can anyone tell me if I can put a new (TPS model) set of carbs from a GS 500F on this bike and just leave the TPS unplugged? Would that work? I have heard of doing this with dirt bikes, so I assume it should work with this right?
Also, is it possible that the P/O "hollowed" out the jets when he attempted to clean them?, and now they are much bigger?
Any help/suggestions are welcome :thumb:
BTW, looks like stock jetting from what I can make out on the jets (127 something on the mains, 17.5 on the pilots, and a "6 something" on the mids...)
I would check the petcocks before anything else. Start from the top and work your way down.
Check out my thread for some other replies:
http://gstwins.com/gsboard/index.php?topic=58643.0
I read your whole thread today before posting up. I rechecked all the problems that you had to make sure I was not overlooking the same issue on mine. The petcocks are next on my list.
Quote from: adidasguy on January 28, 2012, 01:16:20 PM
Where is your fuel? Do you have the tank on or are you using a spare test bottle of fuel?
Fuel is gravity fed. If your fuel bottle is much higher than your tank would be, too much force of gravity and the floats can't stop the fuel from entering the carbs and it squirts out the carb air intakes. How do I know? Been there. Done it.
Lowered fuel bottle to no more than 1 foot above carbs and all was OK for testing.
that is what is happening I think......although, I am using the tank itself with it pretty much in place.....Would this mean that the petcocks might be an issue. (tank is sitting in place, however the two 12mm bolts at the rear are not bolted in place so it makes it easier to turn the tank petcock off and on)
You didn't say where the fuel was. In the tank? Extra fuel bottle?
Note how high the fuel bottle is? Way to high and will flood everything because the floats don't have enough force against fuel and all that gravity. Location of your gas supply when not using the tank is very important.
(http://i1206.photobucket.com/albums/bb442/adidasguy/GS500/trey_on_IV.jpg)
There is about a gallon of fuel in the tank and it is hooked up. The tank is sitting in its rightful place, just not bolted in......I am using it as my fuel supply, not any external supply bottle. Sorry for the misunderstanding. But your issues are the same as mine......does that mean my petcock is FUBARRED?
Quote from: bombsquad83 on January 28, 2012, 02:42:48 PM
I got a K&L carb rebuild kit when I rebuilt my carbs. I had the issue of fuel coming out the air jets to the airbox side too. Then I took out the needle valve and compared it to the one I had replaced. I realized that the new needle valve was actually shorter than the original. This was causing it not to close properly despite proper float height. Check yours and see if you have the same issue.
Also, those float heights are slightly low. I believe my manual said 14mm +-1 mm. I could be wrong, I don't have it in front of me.
I just double checked the service manual.......K1 and newer models float height is 13mm +/- 1mm. The replacement needle valves and seats looked identical to the ones I replaced...Also, I had the same fuel dumping issue with the old ones...just ruling them out as a possible cause...
I bought a ninja 250 once that so much fuel was running in that the oil level was way high and smelled like fuel more than oil. Turned out the diaphram that controls the petcock was shot and fuel would run straight from the tank and right into the intake port. You could check this by disconnecting the fuel line from the carbs, then turn the petcock on with the motor off...no fuel should come through.
Quote from: racer59 on January 28, 2012, 03:23:00 PM
I bought a ninja 250 once that so much fuel was running in that the oil level was way high and smelled like fuel more than oil. Turned out the diaphram that controls the petcock was shot and fuel would run straight from the tank and right into the intake port. You could check this by disconnecting the fuel line from the carbs, then turn the petcock on with the motor off...no fuel should come through.
The petcock is the very next thing to check. :thumb:
Geez, this has run off the rails. If the float needles are working, there is only one way for the petcock to cause fuel to run into the airbox: through the diaphragm and down the vacuum hose into the carb. So pull the vacuum hose off. Is gas coming out of the hose?
Quote from: Paulcet on January 28, 2012, 03:47:03 PM
Geez, this has run off the rails. If the float needles are working, there is only one way for the petcock to cause fuel to run into the airbox: through the diaphragm and down the vacuum hose into the carb. So pull the vacuum hose off. Is gas coming out of the hose?
Checked the petcock, put the tank on and turned the tank petcock to the on position. No fuel coming from the carb suppy line unless I draw air from the vacuum line...same effect in the Res position. Gas will dribble out of the carb supply line when the petcock is in the prime position. That rules out the petcock, i think.....Right?
OK, you have fuel supply, and the petcock appears to be working.
I'll let others comment on your carbs, and whether they've been assembled right.
I always check valve clearances on any new-to-me bike at the same time I tear into the carbs. You'd be surprised how many carb issues are really valve-clearance issues.
Quote from: Paulcet on January 28, 2012, 03:47:03 PM
Geez, this has run off the rails. If the float needles are working, there is only one way for the petcock to cause fuel to run into the airbox: through the diaphragm and down the vacuum hose into the carb. So pull the vacuum hose off. Is gas coming out of the hose?
You and me both... :dunno_black:
If your floats and needles are functioning properly, and you are using the tank instead of an external fuel supply, there's no way in Hades that the petcock can cause flooding of the motor - unless it's doing what Paulcet suggested - running fuel through the small vacuum line into the carb, which is something it
should not do. If that's happening...that's the problem.
You need to re-check your float height and be sure that all your float and needle related o-rings are in decent shape. Also be sure the floats aren't
stuck open or sticking intermittently.
I just remembered something about the petcock issue! Fuel was actually running through the vacuum line and into the intake port.
I would question any and all hose connections/routing by the PO :dunno_black:
Quote from: Suzuki Stevo on January 28, 2012, 07:59:25 PM
I would question any and all hose connections/routing by the PO :dunno_black:
I will go over the entire assembly next chance. That's the only other thing that I can think of now too. Maybe the P/O did not put the carb/fule/petcock lines all back the proper way when he re-assembled it......Does that make sense? Any thoughts on what lines may be crossed to give me WAY too much fuel?
I have reshimmed the valves within spec since I took ownership of this bike, I have double checked them all several times to be sure that I was doing it right with this parallel twin (the service manual is a bit confusing for checking the clearance on the left cylinder ex valve)........
I will do a compression check for each cylinder tomorrow......anybody know what an acceptable range is for this bike?
The best that I have had this bike running was a while ago (last month) when I turned the tank petcock almost off, put the main petcock in the prime position, pulled the vacuum hose off the carb, and cranked it.........It would run at a low idle regardless of choke position, but would stall when I touched the throttle. The bike would idle low for about 5-10 seconds, make a slight popping noise inside the carbs (minly right side) then the idle would go even lower/sometimes stalling. This is the 1st opportunity that I have had to swap the needle valves/seats since that last time.
Here's a diagram:
(http://gstwin.com/images/how_to/fuel%20hose/www_gs500_de_HoseRouting.jpg)
:technical:
DAMMIT!!!!!!!
Looking at your diagram, does the fuel supply from the petcock go to the lower or upper "T" on the carb?
Looks like the upper "T" is for the carb vent line that goes above the carb body and over the airbox.....is this correct? And the fuel supply goes from the petcock to the lower "T" on the back of the carbs???? is this right?
I have an eery feeling that these lines might be crossed,.......
Well, from looking at it in the dark garage, I think that is exactly what happened!!!! :technical: The P/O must have put these lines back on wrong and couldn't get her started. When I looked at the bike, I put a jumper box on the battery and sprayed some starting fluid in the airbox and she fired up briefly, so I bought it. When I took the carbs apart, I never even had the thought that the P/O had incorrectly routed the lines and I re-assembled it like it was each and every time..............
Hopefully (fingers crossed) this is the case, I will find out tomorrow. If that is it, I owe you a beer or three for pointing out the obvious to me :cookoo:
Upper T = carb vent
Lower T = Fuel input
Quote from: Kijona on January 28, 2012, 09:51:47 PM
Upper T = carb vent
Lower T = Fuel input
:cheers: Hopefully this is the issue. Should be up and running tomorrow if this is the case. I will let you know in the morning.
Quote from: craigs449 on January 28, 2012, 09:55:06 PM
Quote from: Kijona on January 28, 2012, 09:51:47 PM
Upper T = carb vent
Lower T = Fuel input
:cheers: Hopefully this is the issue. Should be up and running tomorrow if this is the case. I will let you know in the morning.
If those were reversed THAT is what is flooding your carbs. You can know the difference easily because the vent is just a rubber T-thing whereas the actual fuel input is a more sturdy plastic. Consequently, the fuel input is usually harder to rotate.
Well, That was the main issue. I switched out the lines and put it all back teogether and fired it up. Now I have to deal with a high hanging idle (around 5000 rpm's). The throttle cables don't appear to hang up, and the manifolds appear to be in good shape with no obvious cracks. I have stock jetting and only have the fuel screws out 1 1/2 turns from seated for starters. I am hoping that it's just a really lean condition with the fuel screws at this point. i will turn them out to 2 3/4 turns to see how much of a difference that makes. i will probably hit Buddha up for rejet kit so I can run a bit richer. All in all, It runs now which is 100% better than when I bought it! :woohoo:
When I wrenched for a living, far too much of my time was spent undoing something that somebody before me had done that thought they knew what they where doing :mad:
(say that 10 times fast)
Usually 3 turns is good. That's almost certainly your issue.
One other suspect issue is the absence of and/or worn out sync port o-rings. Check those if you can. Shouldn't need to remove the carbs for that.
Quote from: Kijona on January 30, 2012, 12:22:54 AM
Usually 3 turns is good. That's almost certainly your issue.
One other suspect issue is the absence of and/or worn out sync port o-rings. Check those if you can. Shouldn't need to remove the carbs for that.
What the hell is a sync port o-ring? And where is it?
Quote from: craigs449 on January 30, 2012, 06:03:28 AM
Quote from: Kijona on January 30, 2012, 12:22:54 AM
Usually 3 turns is good. That's almost certainly your issue.
One other suspect issue is the absence of and/or worn out sync port o-rings. Check those if you can. Shouldn't need to remove the carbs for that.
What the hell is a sync port o-ring? And where is it?
It is the small oring that sits under the black plastic diaphragm cover. It seals the small opening that have rubber caps and clips that is used for syncing the carbs.
Part number 26 on this fiche...
http://www.ronayers.com/Fiche/TypeID/26/Type/Motorcycle/MakeID/2/Make/Suzuki/YearID/34/Year/1993/ModelID/7106/Model/GS500E/GroupID/307499/Group/CARBURETOR
Quote from: Kijona on January 28, 2012, 09:21:46 PM
Here's a diagram:
(http://gstwin.com/images/how_to/fuel%20hose/www_gs500_de_HoseRouting.jpg)
Just noticed you have a 01 GS and above pic was for 89-00 GSs, the 01-02 models are the only GSs that the fuel lines from tank to petcock crossed. There were 3 different petcock styles over the years. If you connect the fuel lines like the pic shows you are going to switch to reserve one day and discover you have already used the reserve fuel. Don't ask me how I know, I have a 02 GS. :oops:
(http://img.photobucket.com/albums/v443/jcp8832/GS500fuelcocks.jpg)
IDK if it helps but..
My tps is umplugged, the float covers w/ the vac lines are plugged, and will be replaced by black tops eventually, and anything emissions related is removed.
This allowed me to do the ignition advance without the newer electronics kicking in and stopping it.
The tps shouldnt do anything to hinder starting if its unplugged or mission, because the bike will go into the standard ignition mapping, not the "smart" one
Quote from: gsJack on January 30, 2012, 07:59:24 AM
Quote from: Kijona on January 28, 2012, 09:21:46 PM
Here's a diagram:
(http://gstwin.com/images/how_to/fuel%20hose/www_gs500_de_HoseRouting.jpg)
Just noticed you have a 01 GS and above pic was for 89-00 GSs, the 01-02 models are the only GSs that the fuel lines from tank to petcock crossed. There were 3 different petcock styles over the years. If you connect the fuel lines like the pic shows you are going to switch to reserve one day and discover you have already used the reserve fuel. Don't ask me how I know, I have a 02 GS. :oops:
(http://img.photobucket.com/albums/v443/jcp8832/GS500fuelcocks.jpg)
Thank your sir, I am putting her all back together today and hopefully riding her into work for the 1st time. Still waiting to take delivery of a new OEM front tire to spoon on for inspection. I will be turning the fuel screws out to at least 3 full turns to assist in the lean condition until Buddha gets the restock of the bigger jets that I need.