SV experts @TWF2 @RRP 1st Gen SV 650...stock carbs. Rear carb only leaking. No other issues I can see. Gas comes out the hole near the top of the carb, marked by green arrow. Pretty good flow, especially after closing throttle. Is this due to leaking diaphragm or ??? Thanks,
The problem is your not running Flatslides... Seriously humbled to be even mentioned in the same breath as Zoran. He's the expert, I guess or ask him questions privately. I believe there is supposed to be a vent tube there routes back into the OEM overflow. Can't say for sure as I have flats on all mine.
Correct answer I don't remember last time seen stock carbs, at least 15 years. Your bowl is overflowing most like, either needle valve or needle seat.
I can’t see past the carb, but, there should be a vacuum-operated petcock on the tank outlet. What I CAN see doesn’t appear to be one. If not, your carbs are receiving fuel, all the time. You need to have a petcock, of some sort. As mentioned, the needles and seats probably need replaced. I’d do the bowl O-rings, too.
Petcock is not visible on that picture, it is below that brass fitting (fuel level sensor). You can check if petcock is working properly by simply disconnecting fuel line from it. If fuel flows from tank petcock is not working. In that case you need to clean vent pin hole located inside petcock.
Technically, it's the intake stroke that sucks, not the carb. Carbs just regulate the ratio of fuel and air.