mxnhid ,I haven't tested off-road yet , in the middle of some body work.I probably won't be able to give it the "ultimate" test.
DaveAZ tested the hell out of the bowl seal/vent drill trick tho :http://www.figmo.net/farc/farcdetail.php3?i=162675
If I were you ,I'd follow his lead.6 screws, unhook choke rod , & your ready to JBweld/drill.
Whistle tube = vent chimney = just extending the bowl vent as high as top of air cleaner .
I measured stock Sami carb = 26/30 venturis.
Stock Toy 22R carb = 32/40.
DannyL , if you want to measure Pony , just measure diameter of holes on carb bottom.
I believe my OLD weber has slightly different top & bowl vent setup than newer ones.
When you buy a new 32/36 K600 model kit (low perf) jetting is 47/47 idle, 105/110 mains ,155/160 air corrections.
I'm at 7500' so I bought 45/47, 105/110, 160/165-so far so good.
That's all from this corner