Help....Gas everywhere !!

[Jeff Pattee]

This is something that I have not run accross before....Gas was running out of #4 carb...I tapped on the float chamber but it kept running out. So I removed the bowl, trimmed the gasket (just in case), removed the float assy.. With the needle out, I held my finger over the needle valve fitting and turned on the gas to check for any other leaks and to my suprise, gas came out in about every place that it could under the carb ......I thought that the gas had to go thru the needle valve into the bowl before it went anywhere else....Mikuni carbs.....any thoughts???

[cywelchjr]

I'm guessing you have the model III's with the seat that's held in by the screw with a little finger thing over the edges of the seat? If so, there is an o-ring that goes bad around that seat, and it's gotta be replaced. Make sure you use viton so it doesn't dissolve in our wonderful new gas though.

[natemoen]

Cy is probably right, but make model and year please! Welcome to the site!

[Jeff Pattee]

Thanks

Thanks Cy, I think I know the ring of which u speak....and the best part about it is that I don't have to remove the carbs to get to it !! I am soooo lucky this happened to #4.....I just finished rebuilding my beloved bike (rings, valves) and was starting it up for the first time....the last thing in the world that I wanted to do was wrestle those carbs out

[Ken Talbot]

On the early model carbs, there are four black "T" fittings between carbs - two upper "T"s and two lower "T"s. One set is between carb #1 and carb #2. The otehr set is between carb #3 and carb #4. The upper "T"s are fuel bowl vents and the lower "T"s are fule supply. If you have inadvertently plugged a fuel line onto either of the upper "T"s you will ge fuel spilling everywhere.

JAT..

[natemoen]

Now I am leaning towards kens answer now that i see you have a 78, and I would assume you have the early carbs.

[Jeff Pattee]

Gas everywhere

The fuel and air lines are proper, and yes that would cause gas to spew into the airbox....this problem is specific to the #4 carb only...I have had them all apart before and cleaned them up and they have not been a problem up until now. I have put thousands of miles on the bike since the cleaning.....I thought that I knew what Cy was talking about, but now I am scratching my head..... In the Clymer manual on page 147 there is an exploded illustration of the carbs, I cannot find an O-ring listed.....Could someone have a look and get back to me??

[natemoen]

If you have a 78 and the early style carbs to match then the float needles are screw in and there is no o ring.

You said gas was coming out of the carb everywhere, can you ne more specific? Where is everywhere? I am starting to think maybe the fuel T is failing and leaking gas. that is the only place fuel can come from upstream the float valves.

[crazy steve]

.....I thought that I knew what Cy was talking about, but now I am scratching my head..... In the Clymer manual on page 147 there is an exploded illustration of the carbs, I cannot find an O-ring listed.....Could someone have a look and get back to me??

The Clymer diagram is for the '78-79 carbs and doesn't show the o-rings that the newer carbs use. If your float needle valve seat (part 27 on the diagram) screws into the carb body, you have the early carbs. On the later carbs, this valve seat is just pushed into the carb body (sealed with an o-ring) and retained in place by a 'finger clip' and a small screw. The later carbs also don't have the separate bowl vents; they only have the fuel tees, with the bowl being vented internally in the carb.

You do have the gasket between the seat and the carb body don't you? (Shown, but not identified on the diagram; it's between parts 26 and 27). If that's missing or damaged, you'll get a leak. If it's in place and good, then you may want to pull the carb and make sure you don't have a crack or pinhole in the carb body itself.

[Jeff Pattee]

Thanks guys

It ended up being the 'T' connector in the gas line....If I would have had more light and patience last night, I would have seen it. Since I just rebuilt the engine, I decided to change to rubber gas line. I read a post about the difference between single wall and double wall and quickly realized that I had purchased 7 ft. of double wall. I decided that since I had the carbs off, I would put 4 inches of the double wall on the 2 Ts (between the carbs) to make it easier to change over to the single wall rubber at a later date.....It was a VERY snug fit to get the line between the carbs, and in doing so, I cracked one of the Ts. It was my good fortune that my local junkyard/recycle/used motorcycle parts house had a rack of 4 cannibleized (sp) carbs that he sold me for 5 bucks BTW this is where I bought the new double walled gas line....he didn't have single wall Thanks again everyone for your help

[natemoen]

Glad ya found it!

[DGXSER]

Yeah, I know some folks use that double wall stuff with no issues, but for me, it also flaked off when I pushed it on the Ts and plugged my float valves open. I spilled alot of gas figuring that one out!