Actually the air/fuel mix screws or pilot screws (one for each carb) are accessed from the front of the bike going between the 2 radiators. I just rebuilt my carbs so I know this. The screws are D shaped so they take a special tool to adjust them that is about 16 inches long, if you are not removing the carbs from the bike.

I am not a guru on carbs or the adjustment of, but I have knowledge gained from this forum and from rebuilding my own.

The screw accessed thru the right side of the bike thru the fan is for syncing the carbs.

 

Well, I'm glad to hear it isn't so simple. My guess is the procedure is involved enough it would be onerous to post here. I'll check my manual and see if it gives a good guide. Sometimes it is hard to understand the procedures as they describe them, because they don't speak English as clearly as folks on here.

 

The idle speed screw turns hard on most bikes. You might need a little help from a pliers. The cable is pretty strong. The only purpose of that adjustment is idle speed and will have no affect on your issue. The mixture screws are accessed through the front of the bike after you remove the grill. You should notice a couple of dimpled in tubes to access the screws. It is quite a ways back and kind of hard to get to if you don't know what you are looking for. Of course I'm old and half blind so maybe it will be easier to you. Use your service manual for reference.

 

...and the mixture screws will be the outer two. The inner two are the bowl drains. The mixture screws heads won't necessarily have "D" shaped heads. That's only on certain years and if the plastic limiter caps have already been removed.

 

When adjusting the idle speed increase the revs a bit before you turn the knob and then let it settle back. Knob is easier to turn with no pressure on it from the return spring.

 

Not likely adjusting the mixture screws will help your problem at all.

 

Ok, but what does cause the problem then? (I am in the process now of running a tank of seafoam through). Don't know if it's helping or not.

 

There are a few things that can cause this. 1 in particular is right there near the fuel cap and idle adjuster. a diaphragm inside there can leak and cause a fuel odor. This is an easy and cheap fix. You will need to pull off the plastic around the radio to access it. The name of this piece escapes me at this point.

 

Vacuum fuel shut off valve, if that's not it probably needs a carb rebuild.

 

I wouldn`t be too quick about trying to syncronize the carburetors with the air/fuel mixture screws till I knew that there were no vacuum leaks, put in new spark plugs, air cleaner, and carburetor jets were clear. They are probably set close enough now as long as everything else is working properly. Should be able to turn the knob by the gas cap till it idles at 950 if everything is as it should be. As far as the gas smell, have the drain tubes under covers on left side of bike been drained? Any unexplained gas on tray by gas cap?
gumbyrede

 

The fuel smell is definitely in the exhaust. I haven't yet looked at spark plugs. Sounds like that might be next, since seeing the plugs should help confirm if it is running rich or not. No gas in the catch tray by the cap.
Could that diaphragm cause running rich, or just fail to cut off the gas when the motor is killed? I was hoping it was just a matter of turning a screw on the carb somewhere. :-( If I have to have them re-built I don't know what I'm going to do, since the dealership here is as good as worthless as far as I can tell. The techs seem to only want to work on dirt bikes.

 

If that diaphragm leaks it will suck gas straight into the intake.

 

I had this issue on my '90 Gl1500. Start by pulling the spark plugs and having a look at them. If you are running rich, they will be black. In the old days I would have said they should be the color of fresh baked bread, but with today's gas they might be more white. If they are full white then you are too lean. On mine, I found one side of the bike was black and the other side was perfect, so I decided the problem was with the carburetor on the black side. So I pulled the carburetors. During carburetor disassembly I noticed that the choke (or fuel enrichener) plunger was rather varnished up. I did pull the float bowls off to have a look but they were fine. So I ordered one new plunger and rubber plunger boot. Reassembled, reinstalled and the problem was solved. So my problem was that the choke on one side was not shutting off. So look through the choke mechanism and make sure it is all working properly.

If you really just want to try adjusting screws however, I would start by balancing the carburetors. If one side is working harder than the other you may get a fuel smell as well. I recommend this tool for the balancing http://www.beemerboneyard.com/carbtune2col.html
They make a 4 column unit as well. I also have a KZ1000 so I have a 4 column unit.

Good luck.

 

Dave and Lucky One - I will check both. That diaphragm well could be the issue. If that looks ok, I'll start pulling plugs and see what they look like. I appreciate your knowledge.