Float Orientation....

[yamaroo82]

I ripped the carbs out of my XJ11 as I was getting gas in the airbox. If I compare the float orientation on the Yamaha exploded parts diagram on page 4-1 of the service manual to the picture on page 4-4 of the service manual (and the way the floats are actually installed in the carb), the pictures are contradicting each other. I'm thinking that the picture on page 4-4 is correct. Can anybody verify?!?!?

[SFerinTEXAS]

Maybe you should explain further. My first reaction to your post was WHAT???

The floats can only mount 1 way.

[ManagerMike]

Ditto on the "WHAAAAT?"

[yamaroo82]

I know... It's hard to explain. It's a definate "What the?!?!"

Look at the picture of the exploded parts diagram on page 4-1 of the Yamaha service manual for the XJ1100. Then compare to the the picture below paragraph #7 on page 4-4. Unless I'm smokin somthing, the float orientation doesn't match between the two. My neighbor came over and we compared them as well. He's seeing the same thing; that the floats are 'down' on one picture and 'up' on the other. You'll have to break out the manual and look.

Thanks for trying to help me out...

[ManagerMike]

ok, funning aside, gas in the airbox is almost always a symptom of float valve issues (needle and seat) and less commonly of the float(s) alone. It is possible that you have developed a peforation of one or more floats, but it is more likely the valves that are the gremlins messing with you.

[ManagerMike]

On a similar note, if it was running well, and the reason for your surgery was the fuel leakage isuue, then the float config you see on your workbench is the correct one, and the one in the manual may be suspect. The float valve and the fuel shutoff mechanisn from the tank would be the most likely criminals to pursue in your investigation.

[yamaroo82]

ty for the fb MM!!!

The float bowls look 'clean' and I'm rebuilding the petcocks so we'll see what happens then. Any other ideas and feedback are welcome.

Love the old bike but good help is hard to find. Great to have willing help. Thanks everybody!!!

[yamaroo82]

p.s. It is running well. Only issue is gas in the airbox.

[SFerinTEXAS]

Are you using the octy valve? and is the problem occurring when running or sitting? Or both?

[yamaroo82]

octy valve?!?!? Please help. No comprende...

Gas comes from the airbox only when sitting. And it's seems to be intermittant too. Was having issues being 'wet' one weekend, 'dry' the next as well for a thousand mile trip and then showed up 'wet' again the week after. And since I've had issues with the gas in the airbox, the bike has become a pig at idle too. Idles around 800 - 900 rpm instead of 1100 rpm. Once it's up to speed, it's runs like a champ! Aarrrgh!!!!

[TopCatGr58]

Hey Yamaroo,

You're right, the manual image on 4-1 is INCORRECT, it shows the deeper part of the float body going down into the BOWL, but they go into the carb body instead!!! Very interesting, and this is an official SERVICE MANUAL!?!?

Remember, the float valve seats have o-rings on them that can shrink and also cause leaking. Also, did you say you replaced the float valves?? The rubber/viton tips can harden, and get a groove worn in them, etc. so you may need to replace them if they are 8+ years old!

The XJ along with the Specials(XS's) came with a vacuum control fuel valve called the Octopus...mounts on top of carb #2, and have a bunch of fuel hoses going into and out of it before it gets to the carbs! They can become faulty as well. Some bypass/remove it completely, others rebuild it! YMMV!
But if you're getting fuel in the airbox, the carbs are leaking no matter what the Octy is doing! Have you checked your OIL to make sure it hasn't been contaminated with gas...bad for bearings, engine!

T.C.

[CatatonicBug]

"Octy" is the term given to describe the fuel valve that mounts to the top of the carb bank. The vacuum from the intake boot on the #2 cylinder connects to the octy, allowing fuel to flow only when the engine is turning. Some folks round-file that item to simplify things when it "gets in the way" or causes more problems than it solves.

**Edit** Yeah, what he said

[SFerinTEXAS]

Was having issues being 'wet' one weekend, 'dry' the next as well for a thousand mile trip and then showed up 'wet' again the week after

Looks like you got your fun before the work. Now its time to find out how that baby ticks.

[yamaroo82]

Whew... thought I was going nutz there for a second. Haven't replaced the float valves. Just opened the carbs tonight. I think I had some gas in the crankcase but not much. Changed right away. I'll keep my eye and nose on it once I get everything back together.

Roger the "octy" and it's in place. I'm a newbie on the XJ with only two months on the books. I'm going to focus on the floats, put her back together and see what happens.

Like SFerin Texas says, I'm just starting to learn how this baby ticks... It's going to be lot's of fun!!! Love the site and again, thanks for all your help and feedback. Any and all tips welcome!!!

[SFerinTEXAS]

I wish you good luck on this journey. I cut my teeth on the XS. Was a big heads up on the XJ. Just don't let frustration stop you.It will try.