[pilotdude]

Air vent joint pipe. This plastic part runs between each bank of carburetors and has a tee fitting. Does anything connect to this tee fitting? Just got this bike and it runs very rough and has poor idle. Nothing is connected to the tee on either bank

Thanks for your help

 

[DaveO430]

I think those go to the air cut off on the bottom of the plenum.

 

[pilotdude]

I will take a look. thanks much. They are facing up, probably installed wrong

 

[glhonda]

You have two sets of pipes on each pair of carbs (4 in all)
The lower set have hoses that are connected to the air cut valve. The other two are for evap emissions and only used on California models. If they're not connected, they probably aren't used.

 

[Bike...and Dennis]

As GLHonda says, two of those are hoseless.
Your lousy idle could just be a sync problem or may indicate plugged up idle jets, or circuits.
Do you know anything of the bike's history?

 

[pilotdude]

The bike has been sitting for a year. Seller said the carbs have just been rebuilt, 2 days before I took it. Riding the bike home (40 miles), it started running poorly and got worse. I knew it would need some work but the price was right, nearly free.

56,000 miles and in very good condition cosmetically.

 

[wildman]

I'd check for old/bad gas first. Maybe check the fuel filter. I've learned to check all the easy fixes first. If it ran ok, then went downhill, it might be just crappy gas or some condensation in the tank.