Carb sync'ing on GS500E

[cyrusyn]

Hi,
I was gonna do a carb sync job on 2000 GS500E today and I realized that I needed an adapter to a vacuum take off tube on the carb. What size adapter do I need? 5mm or 6mm?
And how do you take off the vacuum take off tube cover and put your carb sync tube on the carb  no.2 (left side one)? Access to that little sucker seems to be impossible without taking the whole carb off the bike!
T

[lamoun]

I don't understand what adapter you are talking about, so I can't help there (I only use the rubber tube which came with the gauges  )

As for the carbs.. If I am not mistaken, the vacuum nipple on those carbs (1989 - 2003)  are on top. No problem accessing them.

Have you changed them? Are they from a later model, 2004 - today?? If so, yes you have to take them off.
I just put a hose there permanently. 

[cyrusyn]

http://www.cbxmanmotorcycles.com/Motorcycle-Accessories/Motorcycle-Tools/3804-0003-Motion-Pro-SyncPRO-Carb-Tuner.jpg
The 4 brass tubings on the right...

vacuum ports for both carbs are not on the top but on the side of the carb. Vacuum port for the left carb is located under the choke spring and this gives a little access...

[lamoun]

Aha!!! You don't need to use the brass tubings. (Other bikes will.. ex. Honda Shadow 750)

[scratch]

Block up the back of the tank with a 4x4 piece of wood.  Before starting the bike, loosen the caps with a flat screwdriver, that will make them easier to take off quickly when the engine is hot.

[GeeP]

Rather than using the carb synch tool, you can make one with about $2 worth of parts.

Read here:

http://www.650ccnd.com/mano.htm

You don't need any adapters.  Simply pull the little rubber caps off the vacuum nipples on the top of the slide caps (The big round black covers on the top of the carbs), then connect your $1.55 manometer.

[scratch]

vacuum ports for both carbs are not on the top but on the side of the carb. Vacuum port for the left carb is located under the choke spring and this gives a little access...

O.k., I just read this again - that port is for the vacuum-actuated petcock.  The vacuum spigots are on top of the caps as GeeP stated.

[cyrusyn]

Aha!!! You don't need to use the brass tubings. (Other bikes will.. ex. Honda Shadow 750)

why?

[cyrusyn]

I found that the mikuni carb on my 2000 E is not the one BST33SS listed on both haynes and factory manual.
Might be that the previous owner changed it
I tried to find out the model but only saw these 8 letters 01DJ LOY1.
Any have any clue which mikuni model this would be?

[lamoun]

Aha!!! You don't need to use the brass tubings. (Other bikes will.. ex. Honda Shadow 750)

why?

Well, the Honda doesn't have vacuum nipples on the carbs, but has threaded holes (where the tubes screw on) on the intake ports.

As for the carbs..

From the wiki

Here are the 1989 - 2000 (nipple thingy near 14)
http://wiki.gstwins.com/index.php?n=Main.1989-2000


2001 - 2002 (nipple, where 40-41 goes, like yours)
http://wiki.gstwins.com/index.php?n=Main.2001-2002

2003 - current (39-40)
http://wiki.gstwins.com/index.php?n=Main.2003-current

Does any of them seems familiar??

[The Buddha]

I found that the mikuni carb on my 2000 E is not the one BST33SS listed on both haynes and factory manual.
Might be that the previous owner changed it
I tried to find out the model but only saw these 8 letters 01DJ LOY1.
Any have any clue which mikuni model this would be?

Put a pic up.
Cool.
Buddha.

[cyrusyn]

Thanks a lot. Mine looks best like the 2001-2002 carb.
Have any one carb synch'ed this carb?

Aha!!! You don't need to use the brass tubings. (Other bikes will.. ex. Honda Shadow 750)

why?

Well, the Honda doesn't have vacuum nipples on the carbs, but has threaded holes (where the tubes screw on) on the intake ports.

As for the carbs..

From the wiki

Here are the 1989 - 2000 (nipple thingy near 14)
http://wiki.gstwins.com/index.php?n=Main.1989-2000


2001 - 2002 (nipple, where 40-41 goes, like yours)
http://wiki.gstwins.com/index.php?n=Main.2001-2002

2003 - current (39-40)
http://wiki.gstwins.com/index.php?n=Main.2003-current

Does any of them seems familiar??

[bill14224]

I doubt your carbs aren't stock.  Sounds to me like you have a 2001 model.  (K1 suffix)  Check your frame number.  2001 is the year Suzuki switched from 33mm carbs to 34mm.  Then again, maybe the PO put 34s on it trying to make it go faster.

Take it for a ride to get it nice and warm, then remove the tank and rig-up a temporary fuel supply.  Then remove the vacuum take-off cap from the top of the left carb next to the diaphragm, and the vacuum hose from the right carb.  The vacuum hose runs horizontally along the edge of the diaphragm on top of the right carb.  Why not borrow the vacuum hose and use it for an adapter if your manometer won't hook-up directly to the carb?

Start it, raise the idle to 1750 rpm with the throttle stop screw that is right under the carbs.  You can turn it with your fingers.  Then synch the carbs with the screw on the linkage in-between the carbs next to the throttle cable and return spring.  Once you get the vacuum matched, blip the throttle and re-check.  Repeat until it stays matched.

Before you start any of this be sure your valves are in adjustment or you're wasting your time.

Good luck!

[scratch]

Warning on the 'blip throttle': You may suck mercury through your bike.  Roll on smoothly (I synch up to 6000rpms), and roll off smoothly.

Valve adjustments every 4000miles (i.e.: 12,000miles; 16,000miles; etc.).

[cyrusyn]

Thanks guys, I know the procedure. My problem is that the vacuum cap on the left (number 2) carb is located under the throttle cable assembly. This area is so tight that it seems like even a plier won't make it. How do you access this left side vacuum port cab?

[scratch]

If your only hookup is there, you would have to remove the tank and hook up the manometer before starting the bike (and I really hate doing that, but what choice do we have).  Synchronize the carbs quickly, because we're just using the gas in the floatbowls.

Oh, you may not have skinny fingers like I do...that's what you mean.

[fred]

If your only hookup is there, you would have to remove the tank and hook up the manometer before starting the bike (and I really hate doing that, but what choice do we have).  Synchronize the carbs quickly, because we're just using the gas in the floatbowls.

Oh, you may not have skinny fingers like I do...that's what you mean.

Make yourself a small gas tank, it will make your life much easier. Search for Kerry's post on using a coolant overflow tank from an auto parts store. I've been trying to get my carbs adjusted correctly lately and the coolant tank gas tank has been invaluable. I have a friend help out, and right after we take the tank off, I just hold the small tank under the bike's gas tank, open up the tank petcock to get some fuel out, then connect a hose from the coolant tank to the reserve line going into the petcock. That way I can test the whole system for as long as I need to without worrying about running out of gas.

[cyrusyn]

Thanks a lot for your tips guys. However, taking off the gas tank is not a big deal. The big deal is accessing the vacuum port which is deeply buried under the carb's throttle cable assembly. Want to hear from any one who worked on 2001-2002 GS500E carb.

[lamoun]

Thanks a lot for your tips guys. However, taking off the gas tank is not a big deal. The big deal is accessing the vacuum port which is deeply buried under the carb's throttle cable assembly. Want to hear from any one who worked on 2001-2002 GS500E carb.

I have the 2003 - current. They have the vacuum port in the same place as yours.
I just remove the carbs ( I couldn't avoid that too) from the intake ports, just a little, put the hose on, put the carbs back in, screw them, and do the sync'ing.
I left the hose attached to the port for later use. (the other side of the hose is closed with a needle valve)

[cyrusyn]

I guess I have to take the carb off the bike and connect the hose...
What size hose did you fit onto the carb's vacuum port?