[tsubaki]

There is a process possible that may not completely fix the problem that most people frown upon but may give a good indication if the bowl and jets needs cleaning.
Unscrew the drain plugs in the bowls, prime the bubble till a good flow of gas comes out, remember the flow, spray carburetor cleaner into the drain but contacting the orifice toward the jet, continue spraying till it sprays unobstructed, immediately prime the bubble to flush the cleaner out, see if the flow improves.
It may take several tries, it may damage the needle seats and/or float, causing you to have to get a rebuilt kit.
Safest, no cost way is to remove the bowls and go from there. Cleaning stubborn jets can be done with a pick method, copper wire is preferred.