According to the first diagram animation, the open end of my "hose B" is sucking air. Is it supposed to do that?Hi,
There are two small hoses one the inboard side of the petcock, the front one hooks to the right hand carb and provides vacuum to operate the vacuum petcock. The rear hose is there to direct fuel to the bottom of the bike in case the diaphragm develops a leak.
See this thread at the old forum;
After re-reading your question, I am not sure what fitting you are talking about. You may be seeing the float bowl vent??
There should be one on the other carb too.
Have one open fitting on lefthand side bottom(towards inside of my 1982 cx500 carb....need a schematic
of the hose routing please..........
According to the first diagram animation, the open end of my "hose B" is sucking air. Is it supposed to do that?
YES. It actually doesnt suck air in like a vacuum cleaner, it just allows air to be taken in as the diaphram moves. If this did not happen (if the line was plugged) the diapham would not move as a vacuum would be developed when it tried to move via the carbs vacuum.
OK, I'll give you that, but it shouldn't be constant IMO. It would only draw in when the start up process was taking place so as to allow the petcock to open. If it was constant, there is a leak somewhere in the petcock allowing the vacuum from the carb to be present. The only allowable vacuum on that petcock B tube would be minute, and only for an instant, as the diaphragm moved to the open position.