600 fuel/vacuum/carb issue

[Harsh]

Well this will be my first post and unfortunately I have to ask for some help.  A friend of mine picked up a 2000 Bandit 600.  It runs, but it has a few fuel/vacuum/carb issues...not sure which.  The previous owner of the bike stated they cleaned the carbs, but all I think he did was run some cleaner through the tank.

Anyway, the bike starts fine, but has some hesitation as soon as you roll on the throttle and really has a dead spot at the 3-4 k mark.  It will spit and sputter almost like it is missing.  We pulled the plugs and they look great.  I did a sync on the carbs and they were damn near spot on.  We noticed an extra hose coming off the pair system.  It is the small hose that comes from the front of the bike.  It was at one time hooked up to something since the end is flared.  We have the Haynes manual but it doesn't show where the tube connects.  I looked in the pair removal 101 but the pics are gone.  If I were to guess I would say it goes to the T from the vacuum lines coming from the rear of the tank.  The only thing that makes me scratch my head is that there is already a line at the T but it goes nowhere.

Now here are some other things that really make me scratch my head.  Sometimes the bike will behave perfectly.  You roll on the throttle and it reacts as it should and no dead spot.  While it does that that idle is perfect.  Then out of the blue the idle starts to jump around a bit.  I am talking to the tune of an extra 1K indicated all the way down to 900 barely being able to keep itself running.  At the same time the hesitation and hole re-appear.  Plus for no reason what so ever sometimes it will just die.  It could be idling fine then poof it just dies.  When it does that it has a hell of a time restarting.  Could that be a sticking float?

I know this is a lot, especially for a first time poster, but I just want to get my buddy up and running so he can go on some rides with me.  Anything information on where to begin or things to check I would certainly appreciate it.  I have some seafoam that I think I am going to run through the bike to try and clean out any gunk that might be lingering.  Unfortunately for me the Bandit isn't quite as simple as my SV650.

[PitterB4]

Besides the PAIR removal, what mods are done to the bike? 

When it's running poorly, are all 4 cylinders firing?  Maybe I've been hanging out with the B4 folks too much but the jumpy idle sounds electrical/ignition related.

[Harsh]

The pair is still installed.  I justed looked at the 101 to see if it showed where the vacuum lines went.  The only mod is a slipon pipe.  I didn't check, but was told that all four cylinders are firing. 

[crazycletus]

Im prety sure all four are firing because they were all drawing vacum on the gauges (sync kit). Another thing worth mentioning is it ran like a champ when the vacum gauges were hooked up. O ya and I hooked the vacum hose coming of the pairing valve to the tank as discussed. Im waiting till tommorow to see what hapens. Id do it now but the dog and the wife are asleep and I dont want to wake the dog! ...But like harsh said any help anybody can give would be greatly appreciated.

BTW...

Im the new guy Harsh was talking about. 

[crazycletus]

Good aftenoon bandit folk! Im now the proud owner of a used but well running 2000 B6. This following the somewhat gloomy days of a less than desiable performing motorcycle. As mentioned before their was some problems with my carb and or vacum causing rough idle and hesitation. Thanks to Harshes hard work and dedication he was able to trouble shoot and identify a lost vacum hose leading from the pairing valve to the tank. After correcting this the bike runs like a champ.

So if anybody has any questions or concerns please feel free to ask. I would recommend starting with harsh since he is the brains behind this operation. If it is a concen that you may have or perhaps this is not the correct fix and just dumb luck please PLEASE let me know.

To finish Im a novice rider and am currently awaiting my turn at the beginers riding course. Im eagerly anticipating this day because I have run out of streets in my neighborhood and am lusting for the more open roads with the proper endorsments.

Thanks,
crazy cletus

[Red01]

If it runs like a champ with the vacuum gauges attached and doesn't otherwise, I'd look at the condition of your vacuum caps & connections.
(edit- I see you've done this and that seems to have solved it.) 


If the pistons are moving up and down and the valves are opening and closing at the right time (and those parts are in good shape), you're gonna get vacuum no matter if the plugs are sparking or not.  

[crazycletus]

One of the caps was diffrent than the others and fit looser. However the problem with the hesitation and throttle response was fixed when I connected the vacum hose off the pairing valve to the vent tube on the back of the tank . I can expand on this if its sounds strange. Their was a "T" coming of the small vent hose. my concern is that this is in fact the way its suppose to be connected. I would love if somebody could show me a picture of the pairing valve and exactly where the small (diameter) hose goes.

CC

[Harsh]

Did you get a new cap?  If I am not mistaken it is index # 10.  It lists for $2.88, but it might be cheaper to order locally since the shipping would likely kill any deal you would get ordering it online.
http://fiche.ronayers.com/Index.cfm/Module/Main/TypeID/26/Type/Motorcycle/MakeID/2/Make/Suzuki/YearID/41/Year/2000/ModelID/6339/Model/GSF600S_BANDIT/GroupID/261017/Group/CARBURETOR


Glad I could help and so glad I found this site and the fine folks here.  With just a little searching the info was there.  I am with you though CC I would love to know if where you hooked up the vacuum line is actually where it goes.

Now get in that MSF BRC course so we can go riding.  Learn from the pros.

[crazycletus]

I got one month till the course. Ive been riding all afternoon around the block . i even went by ingrams to show him. He thinks it sounds good aswell. its storming right now.

[Harsh]

Learn how to spell you noob.

[crazycletus]

OMG IDK

[Red01]

One of the caps was diffrent than the others and fit looser. However the problem with the hesitation and throttle response was fixed when I connected the vacum hose off the pairing valve to the vent tube on the back of the tank . I can expand on this if its sounds strange. Their was a "T" coming of the small vent hose. my concern is that this is in fact the way its suppose to be connected. I would love if somebody could show me a picture of the pairing valve and exactly where the small (diameter) hose goes.

CC

Sounds right. 

I don't have a pic of the PAIR valve since I ditched mine years ago, but on mine, the #4 carb had a vacuum line that goes up a little bit to a "T" and the other branches ran to the PAIR valve and the petcock.  Now, I just have a line that runs from #4 to the petcock.

[crazycletus]

Thanks for the info. I get how yours is set up.I have a line coming off the petcock to the #4 carb aswell. Im gonna do some more homework. I found somebody across town that has a B6. Once I pop the can on that one Ill know if im set up right or If I just got lucky.

On another note what is the advantage of removing the pairing valve,and exactly what do I need to do to accomplish this?

[Red01]

The only advantage to removing the PAIR system is a small weight savings and easier access for valve adjustments.  Besides the weight savings, there's no performance advantage to getting rid of it.  The main reason I got rid of mine was I went to a Holeshot Stage II jet kit, which replaced the airbox with pod filters, the the PAIR didn't have a filtered source of air anymore and rather that modify my pods to supply it, I just deleted it.

[crazycletus]

  Im sure Ill be on my my to doing then same thing one of these days. This is my first nike and Im just getting started.   

Thanks red, for all the info