Help Identifying Carburetor

[Sym]

Greetings,

My 2001 GS500 has a salvage title, so I do not know what parts have been replaced or what the previous owners have done to it. I am having issues with my carburetor and am going to order parts for a rebuild, but I need to know what year it is first:








Note the throttle position sensor. From my research, this was not standard on the 2001 models. I have looked at part diagrams and have failed find it, except on 2004+ bikes. But those don't have the black heads on the carbs. This is why I am confused.

Some background (and feel free to add input if you could help here too):

My fuel lines sprung a leak a few weeks ago, and during the replacement I destroyed the fuel intake nipple on the carburetor. I had to remove the air box and carburetor (and seperate them) to replace it. After putting everything back together, the bike runs fine. However, recently I have noticed a tiny pool of gasoline appearing intermittently after riding. It takes hours to accumulate, to the point where I dismissed it for several weeks because it was inconsistent. Recently, however, the engine has backfired a few times and I have had trouble getting it started, which has prompted further investigation. I determined the gasoline was coming from the air box drain hose. I have always suspected my carburetor is under-tuned, so now seems like as good of a time as any to do a rebuild, as my research indicates the problem lies in the carburetor configuration.

Thanks for the help
-Sym

[BockinBboy]

Could be two things:

Your float height needs adjustment, or your valve needle seats need cleaned/replaced.  Both of these will allow gas overflow into the airbox. Faulty/dirty valve needle seats will usually only allow gas through while the bike is off, if the frame petcock is on prime.

Also, CHECK YOUR OIL NOW.  If the carbs have been overflowing, it is likely the gas has made it to the oil.  If your oil smells like gas, change your oil.  Gas significantly lowers the lubrication properties of oil, and the GS500 specifically has trouble with low lubrication... plently of spent engine threads on this forum support that statement.

Check you float height first.  If your carbs are off the bike, then go ahead and open up the carb bowls to check the height.  This will also tell you which carb you have (they look like 04+ but please don't quote me on that). 
See this thread below for carb pictures to know which year you have. Notice how different the floats look.
http://gstwins.com/gsboard/index.php?topic=56601.0


See this thread below also.  I have explained how to check float height two different ways, one with the carbs on the bike, and one with the carbs off the bike.
http://gstwins.com/gsboard/index.php?topic=62384.msg728415#msg728415

[Sym]

Thank you. I had been planning to change the oil as I was made aware of this issue while attempting to diagnose the problem originally. I appreciate the advice about the float height as well, it further affirms that is likely the issue here.

I am tempted to simply adjust the floats and see if the problem goes away, at least until their is snow on the road. Then perhaps we will go for a full rebuild...

Thanks again,
-Sym

[The Buddha]

01-02 carbs if it is a US bike.
Maybe 01-03 if its a euro/asia.
Cool.
Buddha.

[craigs449]

Not 01-02 stock carb on US models..........they didn't have TPS....TPS was on the newer 04 bikes......Everything else looks the same as the carbs from my 01, with the exception of the TPS. 

[Sym]

Not 01-02 stock carb on US models..........they didn't have TPS....TPS was on the newer 04 bikes......Everything else looks the same as the carbs from my 01, with the exception of the TPS.

Exactly! I have no idea why it is on there. It wasn't even hooked up to anything.

Buddha seems to know what he talks about though, so I'll order parts based on it being an 01-02... still have no idea why the TPS sensor is on there though  .

I am thinking at this point I will adjust the floats and see if that fixes my problems, but in the long term I think I'm going to switch to the classic lunchbox air filter (which will require a rejet). I eagerly anticipate the prospect of improved performance... I got a chance to ride an SV650 recently and although I never expect the responsiveness of a fuel injected bike from this setup, my carburetor has always been a bit of a dog. It wasn't until I started reading all these posts that I realized that symptoms people complain about (and later fix!) are what I used to consider normal.  Time to get my hands dirty...

Thanks again guys. I really do appreciate the input.
-Sym

[adidasguy]

Where are you located (I wish everyone had their location in their profile.)

Are you in California? If so, maybe you had a bike with a CA modification. Or the carbs were from a different GS500 with CA emissions stuff?

I have a set like that in my collection now. No TPS. Then since there are no vacuum ports on the caps, how do we carb sync them?

Suzuki parts does show that same carb for non-us markets through 2006. 2004-2006 US models had the TPS and other junk on them.  It does show a different part number for the carb float bowl gasket between the US 2004-2006 and the non-us ones. Non-us has same gasket part number as 2001-2002. I'll have to actually take the bowls off some carbs and see if they are really different. Some of the parts do have same part numbers, a few are different.
2007+ all used the same carbs.