Gas Spraying Carb Tee-Fitting.

My 1986 VFR750 (60k miles), on which parts seem to be taking turns failing, is now spraying gas from the end of the tee-fitting that feeds the front pair of carbs. My research efforts suggest that there are o-rings at each end of this tee, and that it is this that has failed. I have pulled the set of carbs, and am wondering how sorry I will be if I try to replace these o-rings myself. For my last effort but one, I opened the carb bodies and cleaned all the inner parts, but that did not involve separating the carbs from each other. For this, I suspect I need to do that. Any hints about what I am in for would be most appreciated.

 

Did you just pull the carbs, cleaned the carbs and now the o-ring is leaking? they will leak til they swell back up and seal. If not just be careful seperating the carbs..the fuel tubes get brittle with age and break easy. Number the carbs..take pictures so you know where everything goes when putting back..mainly the sync springs. Theres a book out that gives good detail on the carbs. Good luck..keep in mind its 26yrs old..things will fail.

 

What dutch said but more emphasis...........MUCH MORE.........on the careful part aboot the tubes. They are stupid crazy fragile. Not as fragile as Tinks feelings mind you but fragile.

 

You'll need to be careful when removing the big-ass phillips- head screws that hold the sides of the assembly together to avoid stripping them. Might be best to use a hammer-driven impact driver with caution. All the phillips-heads need to be struck firmly a few times with a hammer on the screwdriver to break corrosion bonds.Watch for all the springs !! After you discover what Honda want$ for the entire kits that contain the O-rings, you'll be shopping at NAPA (etc.) to find substitutes.

 

There are indeed o-rings on the ends of the tubes. When I went through the carbs on my 500 I separated them, glad I did, the o-rings on the tubes were brittle and cracked, on the verge of failure I'm sure. Separating the carbs is easy, a genuine PITA to get everything back together in the proper places. Pay particular attention to the throttle tab springs (I think that's what they are called), they will go into orbit if you are not careful. Take pix as you go, it will help. I got an o-ring kit from Jamie Daugherty, included the ones for the tubes.

 

Sounds like it is worth a try at least, using all the caution I can with those tubes. When I look online for the o-rings, the diagrams, if I am reading them right, seem to suggest that one can buy the plastic tee with two o-rings as a set (for a bit over $20). Is that what I ought to do?

Part 10 on this page (and part 5 for the back set, which I guess I ought to do at the same time):
OEM Parts

 

And, to round out the story, it all worked perfectly with the cleaned carbs -- not leaks at all at first. Then, gradually, a slight smell of gas, and then, when I last started it, gas gushing out.

 

I did see those tubes made oot of aluminum somewhere and they were not expensive. May be prudent to just replace them while you have it apart......

 

You're sure the drippages are not eminating from the float bowl gaskets or the vent tubes ?? Kinda hard to tell sometimes.

 

I am pretty sure it is from those o-rings. I pulled the carbs with the tank still connected so I could see it all upclose, and when the fuel pump is on, gas streams out along the t-fitting. Way past the drip stage. Probably close to a gallon every couple of minutes, if I let it run. I would guess that the parts that are shown on the OEM lists are original, and fragile, plastic. I have not seen aluminum ones listed.

 

Guess what i've been doing today, i've ultrasonic cleaned all the carbs today and it had made a terrific difference.

 

Problem will soon be solved..Dave, the guy that machines the aluminum fuel tubes for the 1st Gen VFs that are sold on ebay will soon be making a set for the 2nd Gen VFR. We spoke today and im sending him a set of plastic tubes to get specs to start producing the sets..ive already got my order in for 2 of them. Stay tuned..ill post when they are ready with all the details..definately cheaper and will last much much longer..win win for us VFR lovers.

 

Good looking oot Dutch.

 

Pm info when you get the new ones, I am gonna order a few sets.

 

Just wait a second cuz i've got a question: Did you at any time in your cleaning remove the alloy airbox base from the set of carbs ???????????

 

That would be handy info as to a location.

 

We with carbs off, and upside down, it seems that the gushing gas was from the overflow collecting tee. My guess now is that the float was sticking, and the o-rings on the drain are shot, so instead of collecting the overflow, which seems to just dump behind the carbs, it was pouring the gas out between them. Not sure this matters much. Presumably, with the overflow having plenty of years to dry out, those o-rings are effectively gone, and so the gas was coming past that one as fast as the fuel pump could put it into the float bowl. I opened all four carbs and fiddled with the floats and valves, and all seemed to be in fine shape. I put the bike together, and there was no sign of any leaking at all. Not sure what would have made the float stick, or if it is worth trying to fix the overflow tee o-rings.

 

Actually, on reflection, perhaps those lines are vents, not overflow, which would make more sense, and perhaps also explain why they are not gas-tight. Where does the gas from a stuck float normally go?

 

I have taken the airbox frame off the carbs. The first time, when I cleaned them. It also allowed me to do the choke cable after the carbs were installed. (Pressing them back into their boots it the hardest part for me -- it features me standing with both feet on the carbs, pulling myself down using the frame, so that more than my own weight is pressing them down.)

 

Out the vent tubes and also into the intake tract causing a rich mixture in the cylinder connected to the offending carb.