[01 B12] - Fuel, carbs, valves, oh my.

[LowRes]

So I am having some issues with my 01 B12.

Issues:
- Seems to run rich, very sooty exhaust pipe.
- Dies randomly when at reserve (or near reserve) level. Reproduces with gas cap open, so I imagine this isn't a tank vent issue.
- Valves 1.5k overdue for inspection.

What I've done so far:
- Pulled the tank and inspected the petcock and filter. Looked clean, removed from tank.
- Pulled the air filter. Somewhat dirty, no shops locally (Phoenix!) carry a replacement, have to order.
- Pulled the plugs. Plug 1 and 2 very sooty, lots of carbon build up. Plugs 3 and 4 lean, dirty white.
- Pulled the carbs but have not (and hopefully will not disassemble). Broke a clamp where the carb attaches to the manifold side (not airbox side) no shops stock this but I cannot find the part on any if the fiche. http://www.bikebandit.com/2001-suzuki-motorcycle-gsf1200s-bandit-s/o/m6129 Similar to number 12, do you know the clamp I am talking about? I can't find this anywhere, one looks bigger than the other.

So my plan was adjust the idle screws back to 2.5 turns out, as I understand it this is the stock setting. There should be four of these, right? I can't find them documented anywhere in the OEM manual other than that they can be adjusted. When I had the carb out I saw 4 brass colored straight head screws on the bottom (I think, hard to remember here) of each carb. Are these the idle mixture screws?

The bike idles and run well. In short the only issue I was having was the fuel cutting out but I found an inline filter that it looks like the previous owner added to the fuel line. It looked bad so I bought a replacement. I also wanted to make sure none of the vacuum lines where blocked or pinched. I should be able to test the petcock by attaching a line to the vacuum side and sucking on that in order to get the gas to slow while it is "ON", right?

I do a lot of city stop and go with this bike. 7.5k of the last 9k have been in the city. Do you have any idea what might cause 1 and 2 to run rich while 3 and 4 run lean? I don't know if I have the skill to actually open the carb up and go poking around. As I said the bike runs well enough, but could this be a sync issue? Will I need to sync the carbs anyway now that I have pulled them even if I don't mess with the internals? I don't have a manometer.

I think I better get the carbs back on the bike and make sure that is running WELL and then tackle the valves. I have no valve tool and no replacement gasket at the moment so I need to order a few parts:

- Air Filter
- Clamp (carb) - still can't find this on a fiche.
- Valve cover gasket.

[wedge98]

When I had the carb out I saw 4 brass colored straight head screws on the bottom (I think, hard to remember here) of each carb. Are these the idle mixture screws?

Yes, these are your idle mixture screws, all the in is 0, then unscrew out to desired position

You need a carb sync every 3-5K miles, so this will certain benefit your bike.

Since you have the carbs off I would take them apart, but you will need to replace the phillips float bowl screws as they suck and will strip easily.

The dirty air filter will also hurt smooth running of your bike.

if the layout is 1..2..3..4 for the cylinders and 1,2 are rich while 3,4 are lean you could have a huge carb sync issue between your banks.

Good luck!!!