No subs allowed.
I owned/operated an industrial equipment repair facility for nearly twenty years. We worked on pretty much any type of power equipment, much of which was engine driven. I had the luxury of pretty much always having unobstructed access to as many full blown parts and repair kits as I needed (re: carbs). So my methods are kinda useless for older carbs that have availability issues on gaskets, needles, seats, seals, and so on. The chem dip thing is something that I would not suggest inexperienced people use on precious carbs. That stuff can literally consume (aka "dissolve") some of the cruddier castings. Some old cheapo carbs are made of a pewter-like material or older zinc castings. That Chem Dip that I was speaking of can literally dissolve some of those old less-than-good castings (carb bodies) if they're left to soak for too long like overnight or over an entire weekend, or longer.
So take my suggestions lightly, I've little experience with rebuilding precious older bike carbs with few or no replacement parts available. The only suggestion I may have that might be of any use is I know of a way to make you're own o-ring type gaskets (like the oddly shaped rubber gasket that some float bowls use). You can buy o-ring material in bulk on spools of like 100 feet or so. I would guess that "Buna-N" would be ok as far as what material of o-ring material to use. Buna-N is typically resistant to about any chemicals that you're likely to subject you're motorcycle to, such as nearly any type of fuels or solvents. Silicone "solid tubing" (o-ring material) may also be another option, as would Tygon (maybe?). So anyhow, use the requires diameter of o-ring bulk to create the needed seal in the float bowl and snip the ends off very carefully at matching (roughly) 45 degree angles so the cut faces align with one another. Use Super Glue (Ciano acrylic I believe is the non-trade name of the substance for google purposes) to attach the cut ends of the new seal together and call it done. If you take your time and do the splice carefully this method produces a leak free seal every time. This works fer-certain on non-pressurized fuel systems. But I've never used it on any bike with a pressurized fuel system (y'know, the bike has a fuel pump and it's not fuel injected) other than my 1980s V45 Honda Magnas. They use two fuel tanks, one being beneath the seat. So a transfer pump is required to get the fuel from the lower tank into the carbs since that tank is lower than the carb bank's fuel bowls. The unused fuel that was sent to the bowls is returned to the fuel system before the pump, which will continuously circulate fuel at a fixed pressure while the carbs only use that fuel on demand. Those old Honda pumps only put out about 6PSI, so I guess I really took the long way around the block just to say the DIY bowl o-ring is good for at least that much pressure.
WATER PIK RAMBLINGS: They work really well for a lot of things like cleaning carbs. I don't know if they'll tolerate solvents (I doubt it though), I always just used water with them. I went to my local Harbor Freight store and bought an inexpensive benchtop beadblaster cabinet. It's all made of injection molded plastic, is a bright orange color, has a top loading setup where the viewing "glass" (plexiglass is my guess, it's pretty cheapo stuff whatever it is) is tilted to open the box up and allow access to the inside to load or remove parts. Well, I just ran the Water Pik gun-line into the benchtop cabinet through a small hole in the side of the cabinet and used it that way. The bead blast cab used a simple hopper on the bottom to collect the "bead blast media" (in my case it was water) and made clean up and recycling the used water very easy to do. Those Water Piks can put out some fairly serious pressure. If you point that little gun at the right kind of little knook on the carb body water back-sprays everywhere ... EVERYWHERE .. in an instant. Yea, those things can roost the hell out of you right now! So the benchtop bead blast cab worked out just great to keep things contained and under control while using the water pik to clean carbs or other stuff.
OT SIDE NOTE - THE PRESSURIZED FUEL LOOP:Speaking of the pressurized fuel system I was bla-bla-ing about above it reminds me how well that system can be made to work. It's actually a very good method of producing some pretty snappy throttle response even if your bike does not actually require a fuel transfer pump. There is a constant "head pressure" of fuel sitting at the carbs' float bowl inlet valves that just waiting to be asked for. The carbs never ever find themselves fuel-starved no matter how much throttle blipping you do because there is this relentlessly available fuel supply sitting at the ready to keep the bowls filled in an instant. Gravity feed systems cannot always keep up with demand causing sloppy response in certain situations (such as drag bikes, and others). The pressurized fuel loop addresses the livin' shyte out of some of those leaning-out issues. I've personally used this setup on bikes and mondo hyper-active air cooled VWs (dune buggies, I live about 20 minutes from the USA's largest sand dune OHV area known as Glamis and Buttercup). If you're willing to add the extra stuff required to make this work, it can offer some advantages depending on what it is you do with your bike and how you want to ride it. It also works especially well with turbocharged engines that are not fuel injected. So if you're having throttle response issues, as long as any failures and/or tuning problems have been eliminated first, this pressurized fuel loop (got a better name anyone? I don't know what else to call it..) is something I've personally used to solve problems in the past, on 2 strokes, 4 strokes as well.
PICTURE THIS .... There are any number of really excellent submersible fuel pumps these days. And there would be nearly nothing more cool looking than one of those round machined aluminum multi-screw fuel tank access panels on the side of the tank to allow access to the submersible pump and it's workings/wirings. Oh yea, GtR likey.
(haahaa, as if my opinion matters! gotta love self mockery folks).
OK BYE