Engine dies when throttle opened

[XSFLYER1]

My XS1100E will run with the cold starting circuit activated but will immediately die when I try to advance the throttle. I have cleaned the carburetors of everthing I can find and I am also well acquainted with their construction and how they work. I cannot seem to figure out this problem. The floats are set per spec and gas flows from the tank well. The bike had set for a long period of time with gas before I took the carbs off and cleaned them. I suspect a fuel or air problem but I cannot find any of the jets to be plugged at all. I would appreciate any good thoughts on this issue.

I have the Yamaha service manual plus this website as help.
XSFLYER1

[randy]

Hey, Ken, welcome to the site. From your description, it sounds as if the main jet circuit may be clogged. Might as well do a complete cleaning, there are a lot of tiny passages inside the carb bodies that can clog, even though the jets may look clean.

The other culprit that may be your problem is the pickup coil wires.
They can break inside the insulation, causing the ignition to cut out when the advance mechanism rotates.


Do a search here for those subjects and take a look through the tech tips on the left link bar. I'm sure you'll find your answers there. Keep us posted on your progress.

[XSFLYER1]

Thanks Randy, I truly believe now the other passages in the carburetor need to be cleaned in addition to the jets that were already cleaned very well. There are four tiny holes in the top of the carb throat that I feel do not supply gas when the throttle plate starts to open and the engine gets a lot of air but no additional fuel.

I have confirmed that the pickup coils are fine and I have already battled the broken wires associated with them so that is behind me. As an additional test, I disconnected the vacuum advance hose to the pickup coils so they wouldn't move on throttle advance and the problem remained the same. So I concluded that the problem is in the carburetors as originally expected.

When I first cleaned the jets it was after a long setting spell and the jets were very cruddy so I must imagine that the passages that I did not think to clean were also very bad.

I have great confidence now that I will have this beast running again shortly.

Thanks.

Ken Flyer
XSFLYER1

[John]

Did you remove and clean the main nozzles? Some folks call it the emulsion tube. There are four sets of holes in the sides of the nozzles. If you didn't pull them out, then that must be done. The nozzles are what the main needle sits in. You have to remove the main jet, as it is threaded into the bottom of the nozzle, and the slide diaphrams, and the nozzle just pushes up from the bottom. It may be stuck tight, so don't use a metal tool on it. Use a piece of plastic, or a wooden dowel. A metal tool may distort the threads for the main jet. Removing the nozzle will also help you to get some cleaner through the small holes that you described earlier.

[XSFLYER1]

Thanks John,
I have removed and cleaned the emulsion tubes as well as the other jets quite some time ago and then reassembled the unit and that's when my problem became readily apparrent. I believe now that the problem is associated with the passages to the four small holes that are in the top of the carburetor throat. I have never cleaned these passages and therefore they likely pose a fuel restrition problem. The first time I cleaned the carbs after the long setting spell I found all kinds of crap in the jets and emulsion tubes. Therefore it makes sense that these passages to the small holes are still cruded up and pose the problem that is hiding from me.

It seems that there is very little information about these small holes but they clearly allow fuel to enter the carburetor throat immediately when the throttle plate is opened slightly. I found some information in the Tech Tips area of this website and it got me looking and thinking hard about this.

Thanks again.

XSFLYER1
KEN

[John]

If I recall correctly (really taxing THE remaining brain cell here), Skids had a very good website detailing the workings of the carbs. Look for him in the "Members" tab on top of this page, and click on the blue 'WWW' icon next to his name. That will take you to his site.

[Chaluska]

If you stop by your neighboorhoodly autozone, they sell a big bucket with carb cleaning fluid in it, It has a basket you can sit the carb in, lift it up, and out.. etc etc.. Basically a big ol strainer.. You have to take out your.... (crap i forgot the name) all the O-rings have to come out.. and gaskets.. and diaphram.. anything rubber (this stuff is strong!!!!).. Then dip it in.. and I typically leave it in for 4-5 minutes, then lift it out, and dip/lift/dip for about 30 times, then let it sit back in there for 5 more minutes.. and it has been fail proof so far.

[skids]

Here is a link that might help:

http://home.earthlink.net/~sidskids/carbs/spraycarb.htm

And here is one for the schematic, but it is somewhat incomplete as it does not show the breather circuit:

http://home.earthlink.net/~sidskids/carbs/spraycarb.htm

The off-site tech tips is not current for my website (hasn't been for a long time.)

Originally posted by John
If I recall correctly (really taxing THE remaining brain cell here), Skids had a very good website detailing the workings of the carbs. Look for him in the "Members" tab on top of this page, and click on the blue 'WWW' icon next to his name. That will take you to his site.

[skids]

Originally posted by skids


OOPS! here is the schematic:

And here is one for the schematic, but it is somewhat incomplete as it does not show the breather circuit:

http://home.earthlink.net/~sidskids/carbs/carbs.gif

The off-site tech tips is not current for my website (hasn't been for a long time.)

[XSFLYER1]

Thank you for the additional information on my carburetion problems. I am sure that you guiys have hit the nail on the head with the advice you have given me. The link to the carb schematic was helpful as well.

I am confident that I will be able to have the machine out on the street by Labor Day. Finally! It's been a long time coming.

So far I have been very careful and as a result have not broken or screwed up anything in the carburetors.

A buddy and I both bought our XS1100E's in 1978 as brand new machines and toured out west for two weeks and up into Canada's Jasper and Banff Natinal Parks. It was great.

One thing I did after getting the motorcycle was to lean the mixture one notch on the main jet by adjusting the needle height per the book. This made my bike leaner than my Buddy's and I always used significantly less gas than he did with his on the normal factory setting.

XSFLYER1
KEN

[mitch]

carbs

On the bowls there are little holes that u might of missed , they operate the fuel inrichment circuit. make sure u got them cleaned out u might need a small piece of wire....................MITCH