Need a little help with carb tuning

I'm trying to get the carbs into sync on my '86 XJ700XS and it's got me stumped. I have a manual and have read a few articles on the correct steps for carb tuning, but I'm still having problems, so I'm turning to the experts.

First, a little background. I bought the bike a couple of months ago with ~28k miles on it. It has chrome pod air filters on it, but is otherwise in stock condition. When I bought it, it would start easily but would pop through the carbs at idle and just off idle. Carb #1 was the worst, but it would pop through all carbs at least a little. This improved as it warmed up. Also, it would cut out a little above 7000 rpm on the hiway.

So, I removed the carbs, chem dipped them, inspected the internals and reassembled them. All the parts, gaskets and o-rings looked to be in good shape, so I didn't replace anything. I did notice that #3 and #4 pilot jets were turned all the way in. #1 and #2 were both about 1 turn out. During reassembly, I adjusted the throttle butterflys and floats and I set the pilot jets all at 1 1/4 turns out.

Once the carbs were back on, it started easily and idled about the same as before. Float level is where it should be using the clear tube test, so I started adjusting the pilot jets. To get the poping through the carbs to go away, I have them all turned out 3-4 turns and #1 still does it a little. I had always heard that they shouldn't be more than 1-1/2 or 2 turns out. I did the WD-40 test and couldn't find any leaks around the intake manifolds.

So, I took it for a ride. It stumbles a little right off the bottom and wants to pop a little through the carbs, but then runs smoothly and pulls strongly all the way up to hiway speed. It still cuts out a little above 7000 rpm, maybe a little worse than before, but it's hard to be sure.

Once I got back, I checked the plugs. 2,3 & 4 are a nice light tan color and #1 is a little lighter, almost white. That doesn't surprise me since it always acts a little leaner than the rest.

Any suggestions? I"m about out of ideas.

 

First of all, tuning the mixture isn't the same as getting them in sync.
You probably need to clean them several more times to get all the crud out of the passages, especially the emulsion tubes down under the pilot jets that won't come out for cleaning. If you have to you can use small drill bits to clean the jets and make sure they are the correct size, just don't take out any brass unless you intend to open them up bigger. You can also get a jet cleaning kit made by K&N I think at bike shops that has different size rods starting at #30 you use to force through the jets to clean them out.
The mixture screws can be turned out anywhere you need to in order to get the correct mixture at idle but they are fully open after about 4-5 turns and won't get any richer at that point. The fact that you had to screw them out so far and still have popping means the pilot jets are too small and/or still clogged. After they are really clean this time you should adjust all the butterfly valves the same before putting them back on the bike to get them in sync. They should all just be starting to open past the edge of the first tiny hole in the top near the idle mixture screw. Then use a Colortune to adjust the mixture at idle. If it's still pops when you open and close the throttle at slow speeds you need to increase the pilot jets one size then readjust the mixture screws because they interact and try again.
If the airbox and filter or exhaust system is changed from stock then you will need to do this all over again.