Here I go again! 1994 VF750F

I picked it up yesterday. 4400 miles (yes, you read that right) and very clean. Runs like crap so I'm going to do a carb cleaning and sync today. I pulled off the tank and the first thing I noticed was a small rubber air tube coming from between the two rear carbs off of a plastic "T" that connects the carbs towards the top. The rubber tube is 3/8" dia and is not plugged into anything else. Is this just a vent tube not meant to plug in to anything? Seems odd to have unfiltered air entering the carbs if that's what it is.
Also, there is a velocity stack missing from the #2 carb (front left). It looks like someone just forgot to put it back on?? Any ideas?
All the bike has on it is a Two Brothers slip on. I haven't checked to see if the plugs are off of the air screws on the bottom of the carbs indicating they tried to jet or adjust for the new pipe. Stock air filter too.

oh, the title to my post, I bought a mint '86 VF1000R back in 1996 and wish the heck I'd never got rid of that. I've been wrenching on bikes for a long time so I'm looking forward to getting the bugs out of the latest and putting some miles on it.

 

I won't have time to clean and sync today but after some more inspection, it looks like they tried to remove the plenum first but gave up after they broke/lost the one stack. None of the other carbs show evidence of baby huey using a screw driver on them. There is evidence that they finally removed the carbs via the boots. All the boot clamp screws are slightly marred from a screw driver. I've ordered a new stack from Motosport and will do the cleaning and sync when it gets here next week.
In the mean time, I shot some Seafoam down the throats of the carbs, buttoned it back up and took it for a quick spin. It still misses from 0 to 1/8 throttle but feels smooth when I get to 1/2 to 3/4 throttle. I'm guessing there is gunk in the idle circuit jets and the air screws are not adjusted properly either. Next week I'll get it all cleaned up and post back.

 

I couldn't leave well enough alone so I cleaned the carbs the best I could, cleaned the jets and put everything back together sans the velocity tube. It is not as smooth as it could be with a sync but, wow, much smoother than before. I've noticed the TB exhaust is actually quieter now that it's hitting cleanly on all four cylinders. The powerband is very linear.
One trick I must share regarding putting the carbs back on - and I'm not kidding - use KY jelly. You know, the feminine lubricant. It will not harm the boots and the carbs pop on with very little effort. I put the boots on the intake, tightened the bottom bands and started with the front carbs, putting them in first then just a little push on the rear carbs and they go in so easy.
As soon as the stack gets here, I'll do a sync and balance and let you all know how it turns out.

 

One thing to note about the carbs on the 4th gen; They are connected via metal shafts that run through the assembly. It is easy to remove the plenum with the carbs attached to the bike without losing or upsetting anything. I put the new air tube (v-stack) on, did a balance/sync and adjusted the pilot screws according to the manual. The bike runs perfectly smooth now. I'm getting about 46mpg with the bike set up completely stock. I traded my TB pipe for a stock one and UPS lost my TB for a short time. I sent the stock pipe back to the guy I traded with in case the TB never showed up. Of course it did so now I have no exhaust. For the couple of days I did have the stock pipe though, wow. I'm not crazy about not hearing the bike running while on the highway but at least I know it's running as it should. All is well in my world!

 

Honda line mechanic trick > Place the rubber boots / rubber manifolds in very hot ( not boiling ) water, then put them back on.