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**sixtysix** · 11-29-2002, 05:58 PM

The one (there's actually two right?) from the carbs to the air box is a float bowl vent, only on 78-79 models. I have seen people just run someplace safe or remove it and leave the t connector open...DO NOT BLOCK OF THE HOSE(S) OR YOUR BIKE WILL NO LONGER RUN.

Fuel Tee's...I never had to mess with this, Rob has made up new one's at www.motorcyclecarbs.com but they are brass and expensive at 29.99 each(I think), but cheaper than Yamaha would be if they still made them.

Good Luck

**chopper** · 12-01-2002, 05:10 AM

try an autoparts dealer for the t-pieces....or someone who deals in old british bikes for brass ones(cheap)

**ACE** · 12-01-2002, 10:33 PM

I left these hoses open and cranked her up. oh boy!
this was suppose to be cleaned and synced carbs.
The exhaust about killed me, it ran like crap,i smelled alot of gas.
i let it warm up for 5 minutes then shut it down hping it would run better.
It sounded good when i gave it throttle.
I let it cool down an saw the oil looked low now, but i was wrong when i drained it and got a gallon of it to drain out.
The stuff smelled like gas and was thin.
Ok the person that cleaned the carbs srewed up but any one have a reason what caused all this?
I had the luxurey of another running bike that i took the carbs off and tried these.
fired up and runs good.
Now if it was only summer, oh well.
thanks for any tips before i try to rebuild these

**nashville_bill** · 12-02-2002, 08:39 AM

ACE, There are many things in the carbs that could cause the bike to run poorly but only the floats, or needles and seats, will deposit gas in your oil. The floats could be sticking on the sides of the float bowls or could need to be set to the correct height or the needles and seats could be leaking. Were they replaced? Check out the carb tech area here for great info.

If you paid for the carb work - take it back and let them fix it.

**ACE** · 12-02-2002, 10:26 AM

Thanks guys,
I'll pay close attention to this when i attempt to rebuild these things.
After driving 900 miles to buy a semi-restored xs1100 and it runs crappy, well many of us no what i'm trying to say.
I'm real happy another set of carb's from a parts bike made the walls in the shop rumble!

**Ken Talbot** · 12-04-2002, 07:40 PM

Also - remember that a sticking float or messed up needle and seat can still only leak gas if the petcock has failed too. If just one or the other was a problem, you might not ever know it. The fact that you know it means they both need to be fixed.

**skids** · 12-04-2002, 10:00 PM

I had a set of carbs that I cleaned and put away dry. The fuel tees shrank from being dried out and leaked when I finally reinstalled the carbs and put gasoline to them. I rotated the tees to minimise the leak rate and put a cat box below it through the night to catch the gas. The next day, the leaks had all stopped. I think the gas "swelled" the tees.

**ACE** · 12-05-2002, 07:44 PM

I just might try soaking them and see what happens.
they have been dry awhile.
I tried something off the wall to one of them.
Black heat shrink.
It built it up so it was tight again.
It should work but I don't know if heat shrink will stand up to gas.
will give it a try!

**Thumper** · 12-27-2002, 06:21 PM

I've had leaking fuel taps on a couple of my bikes over the years they can easily be stripped down and serviced. You can buy fuel tap repair kits consisting of all the little seals and o-rings inside the fuel tap but make sure to remember the order everything goes in whem your putting it back together or the vacuum valve won't work right. Oh and take it apart carefully because theres a wee spring inside and you probably know how hard they are to find if they shoot off to the other side of the garage.

**shrubberman** · 12-27-2002, 06:34 PM

Here is something that I did when I bought my bike that had been sitting awhile, and was overflowing gas. I pulled the fuel lines loose from the petcocks, drained the gas from each carb bowl {via the drain screw}. Then I tightned each screw, and squirted carb cleaner through the prim fuel line till I filled the bowls back up. Then I redrained the carbs and did the process over two more times. Finally letting the gas fill the carbs in the end, and no more leaks.

**TopCatGr58** · 12-27-2002, 10:29 PM

Originally posted by shrubberman
Here is something that I did when I bought my bike that had been sitting awhile, and was overflowing gas. I pulled the fuel lines loose from the petcocks, drained the gas from each carb bowl {via the drain screw}. Then I tightned each screw, and squirted carb cleaner through the prim fuel line till I filled the bowls back up. Then I redrained the carbs and did the process over two more times. Finally letting the gas fill the carbs in the end, and no more leaks.

Yet....would be what I would say to the above. When you said you squirted Carb Cleaner fluid, was it from a dipping can type, or aerosol spray? The dipping kind, and I think even the spray kind can cause corroding/breakdown of the rubber parts, and the float valve needles have rubber on their tips, so you may have partially disolved your needle valve tips, softened them up enough to work, along with perhaps loosening up the floats. There is also a rubber seal around the needle valve seat, which can get messed up and leak as well if too caustic a cleaner solution is used....so just suggesting be careful with this technique. Welcoming others to add/correct above.

T.C.

**shrubberman** · 12-28-2002, 07:44 AM

It was the aerosol that I used, I won't even use the dipping kind on motorcycles any more, even taken apart.
That is why I didn't pour injector cleaner in the tank. I figured that if I spent 5 to 10 minutes doing this, that there would be minimal damage. Probably less damage that I might have accidentilly done to the bike taking the carbs off and so on.
Besides that I just figured that there was already something wrong with the float valve, it wasn't going to get worse.

**strom** · 12-31-2002, 09:00 PM

This, I picked off http://www.greenspun.com/bboard/q-an...category=CB750 ... it's bout the two air hoses going from carbs to the airbox... between 1&2 and 3&4 carbs... someone wondered what do they do...

----------------------------
That extra line should be routed up and to the left toward the rear of the bike. The purpose of that line is to keep the inside of the float bowls at atmospheric pressure so that your carbs don't have a vacuum pressure in the bowls competing with the vacuum pressure in the intake manifold.
The tube should be pointing toward the rear so that there isn't any wind-induced pressure in the tube, which would pressurize your float bowls, and pointing down, as well, so no water can drip in.

Matt

-- matt reinert (mjreinert@prodigy.net), April 21, 2002.

---------------------------

LP

**strom** · 01-03-2003, 10:19 AM

OK... some new info...

So, anybody who knows XS carb shrine, please HELP!

I noticed that under a bit higher revs, gas pours out of the hole on the right lower side on the back of each carb. What that hole does, is beyond me, but it floods the engine and whatever gas cant get there, runs to the airbox. I tried some K&N filters today after a carb session and I noticed my legs were sprayed with gas. Next I pulled the carbs again and blew some air with a compressor in the back side of the carb, and the piston thingie lifted and air-fuel mixture was sprayed out in front (I raised the front hatch-something-round thingies) and also gas came out of that hole in the rear (the right one). All four carbs do that.

Any ideas... don't be shy and help please!

LP

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