My first ever carb rebuild.

[vileneeds]

Started it yesterday. Found out from the previous owner that he was the second owner in 1980 of the 78 XS1100. It was ridden a few times and forgotten. I will be making a photo library of the the process on my facebook. I will link it soon. I have one question so far. "Are the main jet screws a standard size?" I actually had to scrape it out of the threads with a scribe. It was just rust held in place by the dried gas. The tear down of the carbs is complete and only three of the outer screws need to be replaced but they all are going to. Any sage advice from here. I have already read the carb forum.

[oseaghdha]

Probably a standard metric, I dunno. Are you looking for a tap?
Be careful with that.
If you have the proper size screw, you can file a small notch across the threads, parallel to the shank, and use that to clean out tapped holes. It will remove the crud, but not cut the parent metal. Use lots of PB Blaster or similar.

[vileneeds]

Its is all out. compressed air got it out. I need new ones. two out of the four were bad.

[Erik the Red]

careful now...

Since this is your first carb rebuild, it's important to remember that 1. you can NOT dip the entire carb bank in carb cleaner -it will dissolve the little rubber pieces, i.e. the butterfly shaft seals. and 2. when using spray carb cleaner to clean out all the little passages within the carb, wear eye protection! Those little passageways twist and turn, some straight out at your eye!

Also, somewhere on the site, there's a diagram of the carb that shows where all the passages go. Do a search if you haven't already. It illustrates it pretty well. Carbs aren't super difficult. Just a 3D puzzle that actually has a purpose.

[CatatonicBug]

Vile - First, don't use Facebook as a host for your pictures. When you link to them here, others will not be able to see them unless they have a facebook account, and are logged in.

As for the jets, I don't know if there is a such thing as a "Standard" jet. These are Mikuni carbs, and there are Mikuni jets, and aftermarket jets that will replace them if you need to. I get mine as a whole kit and replace everything all at once, but others choose not to do that, and purchase only the jets they need. Georgefix on ebay is one of the most recommended sources for jets. He knows what you need, and can get just about any jet sizes for you.

[DiverRay]

The replacement screws are easy. take the size you need to ACE hardware, and look in the metric bins. I've found what I need at ACE almost every time. If you are talking about the screws INSIDE the carb bowel, go to mikes XS for parts and jets. He sells everything in pairs for the 650, you just need two pair of everything. These carbs use the "big" main jets, just so you know.http://http://www.mikesxs.net/products-38.html#products This is the main jet page.

[fabricgator]

I'm in the process of my second XS11 carb cleaning. 1st having taken place 4 years ago and I was not thrilled with the results. I also did not have the wealth of knowledge that is available here, now.

The Emulsion tubes: I had not removed them before, so I don't think they are shell game shuffled between the four carbs. I did note last night that there is a difference in the hole pattern appears to be two different configurations. Noted was that carbs 1 and 3 had similar tubes, and 2,4 had the other style. I have looked at the IPC (illustrated parts catalog) for the 1979 XS 11 SF and do see two part numbers, but not where they are designated to be positioned. Advice requested
Note* I found a neat, non invasive way to remove these. I screwed a slide diaphram cover screw into the threads where the main jet holds it in place, and was able to tap or apply pressure to move it the length of the screw. CAUTION: The threads are not an exact match and the emulsion tube is soft brass, I hand tightened and believe I got about four threads penetration before it began to bind. Apply minimal pressure or tap lightly with a hammer and then complete extraction with a pencil as described.

I was just about to start immersion in carb cleaning solution basket, when I read this post about the butterfly shaft seals. That being said, has anyone simmered the carb body in warm soap water...... Carburetor soup?

Then the float level adjustment... I have the brass floats, I am still looking for the measurement and the datum (location to measure to) for adjustment. Additionally, I want to verify the fuel level and operation by using the clear tube method from the bowl drain ports. What should the fuel level be when properly adjusted? I have read how a few millimeters higher or lower may be used to enrichen or lean the mixture across the board. What is the standard datum or fuel level I should shoot for? The picture in tech tips shows a level about even to the bottom of the float bowl screw casting....

My last situation at this point in my cleaning, is the small jets up in the casting within the float bowl, adjacent to the main jet and float valve assy. How important is it to remove and clean OR can they be effectively cleaned without removing them?

In aviation, we use Hoppes Nitro Solve gun cleaner for brass fuel injectors. This is acceptable practice for these and I learned this from attending an FAA maintenance symposium. I want to suggest this as an approved method for our craftsmanship.

Any guidance is always greatly appreciated.

[bikerphil]

The emulsion tubes with the least holes go in the center 2 carbs. If you want to soak the carbs, although not necessary IMHO, just immerse them so the butterfly shaft seals are above the level of carb cleaner. Soapy water won't do much. Yamaha makes a special carb dip that won't hurt the seals if you want to go that way. The pilot jets must be removed (they're down a tunnel in the float bowl under a screw) and the passages cleaned, or you'll never get her to run right. Spray lots of carb cleaner several times thru these passages. You'll probably have to grind down a screwdriver to make a perfect fit for these, or you'll end up drilling them out. Soak 'em down with PB Blaster first, let 'em sit, then lightly tap the housing before attempting to remove them. Measure your floats with the carbs upside down on the bench, from the float bowl gasket surface (gasket removed), to the highest part of the float bulb. Make sure you do both sides of each float, bending if necessary to get them correct. Stock float height is 27.5 mm. HTH

[Larrym]

Dirty Harry, "You feeling lucky today???"

My last situation at this point in my cleaning, is the small jets up in the casting within the float bowl, adjacent to the main jet and float valve assy. How important is it to remove and clean OR can they be effectively cleaned without removing them?

Take a look at part "c" in this pic:


Courtesy of TopCatGr58

And the one on the right in the below pic:


Courtesy of TopCatGr58

These are the jets on the inside of the tower next to the main jet. Imagine if one just sprayed Carb cleaner through the middle. The side holes in the jet might/might not get cleaned. Also, the side holes in the jet are there to connect to other sideways passageways inside the tower which might/might not be cleared when the carb cleaner is shot down the middle of the jet. There isn't a single hole or orifice in these carbs which isn't there for a reason.

Gotta remove them to be sure all is clean/all is well. If left in place then it's a coin toss whether there's crud in there.

See this post from Ken Talbot for a way to measure the float level:

http://www.xs11.com/forum/showpost.p...9&postcount=12

[Larrym]

Carb Bench Test

vileneeds,

Not sure if it's mentioned in the tech tips but after doing all the disassembling, cleaning, assembling, and adjusting of the carbs it was recommended by member prometheus578 to do a bench/leak test before installing them on the bike.

This entire thread is informative but here is the leak test:

http://www.xs11.com/forum/showpost.p...4&postcount=17

Checks the floats, carb Tees, etc BEFORE they're on the bike and you turn on the petcocks/hit the starter button..

[fabricgator]

Thanks guys,

The information and advice you provide is invaluable.

I also have a idle air needle stuck in the #3 carb to ease out of there... I fear the brass needle screw is beginning to torque and I fear it snapping off.... I hate screw extraction. I'm good at it, but hate it just the same.

The pilot jets are already chingered a little... possibly by my own hand 4 years ago. I hate the thought of drilling them out. I'll soak em for a month if I have to just to avoid fudgeing them up.

What is your best recommended sourcing for replacements?

Tell me about something I read here about Dynojet upgrade?
This cycle has plenty of power as is stock for my needs...... do I want to Dynojet?
I am running 4-2 aftermarket exhaust and will want it jetted correctly. The exhaust is nothing fancy nor high performance. I think I may be correct once I get the mixers cleaned and operating as designed.

Any reliable float pin post repair suggestions? I thought I saw someone did a safety wire hoop repair (drill a hole in post and secure it with a small wire) Carb #2 on the opposite of the head of the pin end. Currently, it stays secure against the machined surface by the interference fit of the head end. I think I can let it ride like it is for the time being... but would sleep better knowing it had something. How does JB Weld hold up immersed in fuel?

What is this airbox drilling I have heard mention of?

Thanks for your help, again, invaluable.

[bikerphil]

If one of the fuel mixture screws (outside top front of carb) snaps, the tip will get stuck in the carb throat. The threaded part usually won't snap. A good trick is putting the carbs in the freezer , then popping the broken tip out. Seem to work well, although I have never tried it, others have had good luck. I might have an extra one if you snap it, or you can get a new one from bike bandit. The jets are a little easier to come by. The pilots (BS30/96 type) and the mains (large round type) can be ordered from MikesXs.com and they're in Florida, so fast shipping. BTW, don't be afraid to throw a little heat on those pilot jet towers, that'll help loosen them up too. Drilling the air box will give you a bit more air flow, increasing performance, supposedly. For the float post, I'd wire it up. Me myself, I don't trust JB weld immersed in fuel.

[vileneeds]

Not good at all.

Part "C" in that wonderful pic helped a lot. All four of those are still half in the damn tower. I though they came out aweful easy. In the service manual in step 8 I am told to use needle nose to pull out the main nozzle... If a pic could be posted of one half in and out that would be wonderful because I do not want to muscle fu(l< anything else in this carb. That would be "D" in that wonderfully helpful pic above.

[bikerphil]

Take the main jets out and use a wooden dowel to tap the emulsion tubes out. Diaphrams must be removed first. The emulsion tubes come out the top of the carbs.

[Larrym]

JB Stands for Jim Beam in my book...

Thanks guys,

I also have a idle air needle stuck in the #3 carb to ease out of there... I fear the brass needle screw is beginning to torque and I fear it snapping off.... I hate screw extraction. I'm good at it, but hate it just the same.


Any reliable float pin post repair suggestions? I thought I saw someone did a safety wire hoop repair (drill a hole in post and secure it with a small wire) Carb #2 on the opposite of the head of the pin end. Currently, it stays secure against the machined surface by the interference fit of the head end. I think I can let it ride like it is for the time being... but would sleep better knowing it had something. How does JB Weld hold up immersed in fuel?

For the Idle air jet inside the inlet bell of the air horn I'd definitely do the trick where you grind/file down a screwdriver to make it fit perfectly. Using an ordinary sized blade can work but then sometimes it doesn't and then the slot gets boogered up. Along with applying real penetrant and waiting 24 hours I'd also try lightly tapping the end of the screwdriver during the twisting action. This tends to release some of the downward force the jet may be exerting in the same way an impact driver works.

For an interesting read about the float post repair with some pics see this:

http://www.xs11.com/forum/showthread.php?t=25919

I'm not a fan of the JB weld fix cause it's submerged in fuel. There's no consensus in the members about whether it's ok or not. I see the JB weld as a temporary/make-run fix which if done should start the clock for getting the parts to do a permanent repair which won't come back to haunt you (me...).

Jetting changes are usually done after going through a whole "process of elimination" where nothing else worked: Consider letting what your bike does and how it runs drive the decision to make those jet changes.

Haven't drilled my airbox ....yet...I Would only do so IFF( If and only If...) I'd tried lots of other things to make the air/fuel mix perfect. Besides, recently a member did drill out his airbox in an effort to gain some performance: he drilled the holes where they let in unfiltered air as opposed to the filtered air. Ya sure that you know where to place the drill bit???