So ...need a bit of direction-was carbs, not coil pick up

[JonnyO]

Wait. Hold on there pardner. Am I being pointed at checking the gaskets FIRST rather than o-rings? The PB Blaster is coming today. I'm lost on what to do first. I have the carbs off. THat much I have. I went to move them inside to work on 'em and a bit of gas spilled out. Is it OK to turn them upside down? THAT is how much I don't know about what I'm about to do. I mean a toilet is only a few bolts and a closet flange but if you've never replaced one it's a puzzling idea.
Anyway, thanks.

[Schming]

JohnnyO, please check out these links for help, a lot of experience to guide the future XSessives has been collected. The info generally walks you through every step to achieve the satisfaction of getting your bike running yourself and that's a great feeling.

https://xs11.club/forum/repairs/carb...fuel-system-aa

[JonnyO]

JohnnyO, please check out these links for help, a lot of experience to guide the future XSessives has been collected. The info generally walks you through every step to achieve the satisfaction of getting your bike running yourself and that's a great feeling.

https://xs11.club/forum/repairs/carb...fuel-system-aa

Thank you.

[JonnyO]

JohnnyO, please check out these links for help, a lot of experience to guide the future XSessives has been collected. The info generally walks you through every step to achieve the satisfaction of getting your bike running yourself and that's a great feeling.

https://xs11.club/forum/repairs/carb...fuel-system-aa

THIS IS WHAT I NEED A VIDEO OR PICS OF ...I think.

by Blaine Hoopes
Most of you will already know this but for those who don't this sure made a big difference. I've carefully cleaned the float needles and seats many times but still have a strong gas smell in the garage and once in a while a little drip of gas into the airbox from the carbs overflowing.

I finally realized that my needles and seats were sealing perfectly but the seat was leaking in the carb body. I don't know if you can get that small o-ring individually from Yamaha or if you need the whole kit but I found a set of 6 o-rings at PepBoys (air conditioning hose rings) that were nearly a perfect fit (a little tight but worked well) and cost under $2 for the set. I can leave my petcocks (manual petcocks) turned on with a full tank of gas now and don't get any drips or gas smell in the garage.

The float and float needle act as a fuel valve. On the '80 carb, you pull off the floats and the needle. There is a phillips head screw in a clamp holding the brass seat into the carb body. Remove this screw and clamp and lift out the seat. There is an o-ring around it on the '80 and I would bet on the '81 as well. I just checked and the picture in the service manual is of a '78 and that seat is threaded and has a washer/gasket so this o-ring stuff wouldn't apply to those carbs (1978-79).

Update Feb 24, 1999

After some good insight from Sid (thanks Sid), I thought to look at the float seat again. In good light I noticed the seat had some rough edges which prevented a good seal. I took my drill and put in a 5/32 bit and drilled ever so lightly and for just a few seconds in reverse. Leak solved.

[motoman]

Yes JonnyO, the common float bowl gasket issue IS the first thing to check before any possible o-ring issue. What happens when float bowls are pulled tight back on is the bowl gasket compresses a bit causing gasket to squish a bit forcing a slight bit of it to protrude to inner edge of bowl. As previously stated by LA83, being a common issue with Mikuni carbs, Float clearance IS minimal as it is with these carbs.

[JonnyO]

Yes JonnyO, the common float bowl gasket issue IS the first thing to check before any possible o-ring issue. What happens when float bowls are pulled tight back on is the bowl gasket compresses a bit causing gasket to squish a bit forcing a slight bit of it to protrude to inner edge of bowl. As previously stated by LA83, being a common issue with Mikuni carbs, Float clearance IS minimal as it is with these carbs.

OK. I think I "get it"-what Lab3 was talking about. I think I recall Cajun saying the same thing.
https://www.partzilla.com/product/ka...ccf6654a41f25e
A youtube video at 6:25 shows THIS gasket ( half the price of the XS1100 one at partzilla ) https://www.youtube.com/watch?v=8ZoHFL8hvFI

[DEEBS11]

[JonnyO]

I can attest to this as being the truth. Whoda thunk to read the instructions!?
Little monsters, indeed!

[JonnyO]

So the seats (?) ( o-rings ) I ordered are on the way. Can anyone give me the part number listed in the diagram for the seat and the needle jet that I'll be replacing and the area where to polish?
Also I've ordered 4 bowl gaskets. Will it be obvious if a gasket is creating a problem with the overflow issue I was having? Should I simply replace the gaskets, reassemble and see if it leaks again?
Yes, I'm unclear on the concepts.
They say the only wrong question is the one not asked but I still feel like an idiot for having to ask what is obvious to most of you.

[cajun31]

So the seats (?) ( o-rings ) I ordered are on the way. Can anyone give me the part number listed in the diagram for the seat and the needle jet that I'll be replacing and the area where to polish?
Also I've ordered 4 bowl gaskets. Will it be obvious if a gasket is creating a problem with the overflow issue I was having? Should I simply replace the gaskets, reassemble and see if it leaks again?
Yes, I'm unclear on the concepts.
They say the only wrong question is the one not asked but I still feel like an idiot for having to ask what is obvious to most of you.

Jonny, if you have the carb assembly off the bike you can install the float bowl gaskets and get everything tightened up and simply slowly turn the carbs upside down and back and listen to the floats moving up and down. You can put them close to your ear and listen to each carb and literally you will hear the float moving in each one. Most of the needle jets and seats sold on Ebay Yamaha Xs1100 Float Needle Jet Seat Assembly for sale | eBay, Partzilla, Mike's XS, Old Bike Barn etc... will work. As far as polishing you just need to make sure you don't have any build up or grooves preventing the smooth movement of the needle in the seat. The float has to be able to rise and fall according to the fuel level only. Gaskets protruding and catching the float or crud stopping the needle is not good. I had a college professor that told us on the first day of class that the only stupid question is the one you have that you don't ask. The diagram you have above is not your bike. Those carbs are from a standard. you own a special. The floats in yours are plastic and your needle valve seats have the o-ring around the base seals the seat. The diagram above has a washer and the seats actually screw into the carbs to seal them. The needle valve on the early standards also did not have the rubber base on them. It was simply metal to metal. I say all of this so that you don't order the wrong parts.

[JonnyO]

Say Cajun? Is there a schematic of the XS Special Carb anywhere so that I can get an idea of what the hell I am trying to get to-the seal and polishing the seat/needle? They are off the bike now. I haven't opened 'em up yet. Witing for the gaskets. From what I've read/seen the carbs/bike can be run without the airbox being reattached? Wouldn't one way/simple be to replace the gaskets, reinstall carbs and route fuel lines back on and see if it still leaks before tearing into the o-rings/seat/needle job?

[JonnyO]

The one side seems a little buggered up-where the float bowl sits. Don't know how/when that happened. When I got the bike it seemed like it was too rich to me so I changed the main jets. Plugs didn't get all black after that and to me anyway it ran great. That was in '19. Maybe 2K ago. That was also when I worked at a shop and there was a competent mechanic to help me when I couldn't figure sheet out-like how to route the fuel lines. sheesh

[cajun31]

Say Cajun? Is there a schematic of the XS Special Carb anywhere so that I can get an idea of what the hell I am trying to get to-the seal and polishing the seat/needle? They are off the bike now. I haven't opened 'em up yet. Witing for the gaskets. From what I've read/seen the carbs/bike can be run without the airbox being reattached? Wouldn't one way/simple be to replace the gaskets, reinstall carbs and route fuel lines back on and see if it still leaks before tearing into the o-rings/seat/needle job?

Yamaha Motorcycle 1981 OEM Parts Diagram for CABURETOR | Partzilla.com. You need to proceed cautiously. Everyone has made suggestions as we always do and you need to filter through everything and decide what needs to be done. Gaskets are just one suggestion. By the way that picture you show in your follow up post on the float bowl. That is not bad at all. When you put the float bowl back on with a good gasket it will seal. If the carbs have never been disassembled, you need to be very careful when you go to remove the float pins. The floats have to be removed to get to the needle valves and seats. There are several good tips in the maintenance section discussing those pins. You don't want to break a post. If you do you have much bigger problems. With the carbs off the bike you need to get them dis-assembled so that you can inspect everything. Should have done that to begin with but we are where we are now. Changing jets on a guess is not a good approach unless something else has changed. There is a maintenance tip that does a good job of showing you how and when changing jets to larger sizes should be done. Again it is a suggestion from years of experience and you have to be the judge as you are there and we are not. What you need to verify is what you have and share that with us in pictures and then we can pinpoint things for you and resolve your issue rather then bombarding you with guesses as to what is going on.

[Larrym]

Wouldn't one way/simple be to replace the gaskets, reinstall carbs and route fuel lines back on and see if it still leaks before tearing into the o-rings/seat/needle job?

Mebbe an even simpler mOaR reliable way? (◕‿◕

https://xs11.club/forum/idle-talk-fo...ees#post303550


Translation- Just remove screws/float bowls from all 4 (four) carbs whiles they's upside down, connect a fuel source (OR just carefully use something small enuf to fill the already connected lines to the fuel Tees...), then "BlIP" the floats to get the air outta the lines, and then WATCH. ٩(＾◡＾)۶

(It's called an inverted bench test and comes from one of the greatrest members/contributors XS11.com E-V-E-R. )

FoAr a final clarification? (O_o)

https://xs11.club/forum/idle-talk-fo...564#post303564


Have at it! (^_^)

NOTE- The screws most definitely are NOT PHILLIPS!!!! They are J-I-S. "Japanese Indistrial Standard". Iffin you's waitin' fOaR gaskets then you still gots time to find/buy yurself a set of JIS screwdrivers and get off on the right feets. ( ͡° ͜ʖ ͡° )

[oldyam80sg]

Invest in an auxiliary fuel tank so you don't have to connect to the fuel tank. Way simpler to use.