Where is my diaphragm?

[fredintoon]

Hi Spootinay,
Gawd! What a mess! The gas taps are off a Special. The gas line hookup is an abortion. The carbs look to be orphans.
Gas taps:- cap off the front spigots, absent the octopus valve you don't need them, that leaves 2 gas lines with the "prime" position now being an extra "off".
The stock carbs have a Tee that fits between #1 & #2 carbs to feed them and a second Tee that fits between #3 & #4 carbs to feed those.
The simpest non-octo set up runs a line from one tap to the #1 & #2 Tee and a line from t'other tap to the #3 & #4 Tee.
You can swap the lines lefty-righty to get more room to fit in-line gas filters.
The rubber carb to engine boots should each have a vacuum tapping. Absent the octo they should all 4 be capped off.
#2 stock carb has a vacuum tap on it's body that connects to the ignition's vacuum advance mechanism.
Now, to those orphan carbs.
AFAIK, if the #2 carb don't have the vacuum connection on it's body the bike won't have a vacuum advance and it won't run right.
If you can hook up the gas lines to those carbs so the gas don't pour out everywhere, the bike might fire up enough to see that the ignition works.
Your french-fry strainers are good for nowt, MikesXS sells pods that'll work, they even have XS stamped on them.
Good luck with it.

[crazy steve]

They could be XS carbs with the wrong bowls, I believe you can fit the later bowls on the older carbs....

They're not any XS11 carbs I've seen...

These have the late-style tops and the rear carb bracket right below them like the '80-81 carbs, but lack that style bowl vents in the inlet, as well as the earlier type vent to the enrichener; they do appear to have the early style 2nd tee type vents. That rearward-pointing idle adjuster screw is odd also. The main carb body casting looks sort of like a cross between the early and late XS carbs. As far as the bowls, those can be swapped onto the '80 carbs, but not onto the '78-79 carbs as that brass tube that the bowls goes over was moved slightly.

And Fred's right; if you're missing the vacuum advance hose nipple on the number 2 carb, you'll have a hard time making it run right and your fuel mileage will be in the toilet...

[Aches n Pains]

Spootinay

A suggestion.

1. Pull the carbs and send us pictures of the guts with the bowls and caps removed. You are definitely going to want to clean/rebuild the carbs anyway to make sure everything is open, clean, and adjustable. There are some great references for carb cleaning on the site. Just take things slow - bigger hammer isn't the right answser.

2. Get a set of K&N pod filters. Lots of folks don't like this change but they make carb access so much easier. Might want to rejet the carbs for this change. Again, lots of great references on the site.

3. Leave the octy off. A fix that many/most of the XS riders do. The octy is an unusual design feature and can be a point of failure. Lots of folks cap the prime outlet on the petcocks and just use the main outlet. Only deal is that you want to turn off the petcocks after you ride in case they should leak. You can take one petcock to the inlet between 1 and 2 carbs and one petcock to the inlet between three and 4 carbs or you can put a a crossover fitting (like an "X") so both petcocks feed all carbs.

4. Put a short piece of hose on the carb vent with a fuel filter on the end to keep junk out.

5. Oh, and put a fuel filter on each of the lines from the petcocks so you are not totally dependent on the filter in the tank.


To me, XS carbs are touchy so, if you want to ride this bike, you might as well get used to pulling the carbs, cleaning and adjusting, setting float levels, and synchronizing.

Good luck,

Aches n Pains (Doug)

PS - where do you live? If you're close I could walk you through the carbs bit.

[Aches n Pains]

Spootinay

After looking at your second group of photos, those are definitely not XS11 carbs. For the '79 special, there should be three small hoses and the oval hole in the bell housing facing the air filters.

Is the carb spacing correct for the engine - ie; do the carbs mount correctly to the intake manifolds on the engine or do you have to bend the intakes for 2 and 3?

I would love to know what carbs they are and whether or not they work because XS 11 carbs can be a little pricey.


Problem you have now is to figure out how much work you want to put into these carbs. It is possible you could put lots of hours and time only to discover that you can't make them work.

Wish I could tell you what they are off.

[Aches n Pains]

Wondering if they might be Suzuki. Looks right from the intake bell housing end (two holes plus oval hole). There is a very good tutorial on cleaning/repairing these carbs (BS34 Mikuni's) at:

http://www.mtsac.edu/~cliff/storage/...d_Tutorial.pdf

[Incubus]

I have worked on Hondas and Yamahas (and the occasional Suzi from 1968 to 1987 and I have never seen a set of carbs just like that. I am not sure what they are from. I'm betting Suzi or Kaw. It could be anything, though, since there really aren't "Yamaha" carbs or "Honda" carbs. They are almost all keihin or mikuni.

Patrick

[fredintoon]

Hi Spootinay,
the frame and engine serial numbers will tell you what the bike was when it left the factory.
If the numbers ain't identical the engine has been swapped out. No biggie, they all fit.
If you post a photo of the bike we can tell you what you've got now.
And don't sweat the "Frankenbike" label. XS11 parts can be swapped like Lego to build a truly unique machine.
Whatever you have, it's a great bike.
Once the carbs get sorted.

[ccogswel]

Those carbs look like the ones off a 84-85 Fj1100! Just worked on a set here a couple weeks ago. The only difference is the ones I had worked on didn't have the idle screw where that one is at. But they may be off a later FJ model. Don't know if this helps.

[Spootinay]

oh man i didnt see page two and now i have to read through 8 posts

[Spootinay]

Well my sister took her camera for the weekend so no more pictures far a day or two.


fredintoon:

front spigots capped.two lines from taps to lower carb t's. all four vaccum taps on rubber carb to engine are capped.

i think there are two vacuum taps on the carbs. on each above the fuel taps?

and where do i get the vacuum suction from? is it the hose coming off of the octagon shaped cap just above and to the left of the kick start?

Aches:

I live in palm coast fl. ill be taking the carbs apart and uploading pics soon.
the fully assembled carbs fit perfectly into the intake to carb boots.

incubis:
they are mukini and im starting to think they are an aftermarket carb to fit a wide range of bikes.

ccogswel:
can you tell me if the two taps above the fuel taps are for vacuum lines?

[Spootinay]

Its a Mukini BS34 (CV) carb for sure. ive uploaded more photos.
http://s1188.photobucket.com/albums/...ent=photo5.jpg

what are those four smaller hoses coming off of it for?

[BA80]

Here is a set of 79 Special carbs I have rebuilt for my bike......


This is what they look like from the airbox/air cleaner side;



Here is a pic from the engine side. I am pointing at the vacuum port on #2 carb for the ignition vacuum advance.



What you are describing over by the kickstart sounds like the crankcase vent. That needs to be filtered somehow also.

[Spootinay]

Here is a set of 79 Special carbs I have rebuilt for my bike......


This is what they look like from the airbox/air cleaner side;



Here is a pic from the engine side. I am pointing at the vacuum port on #2 carb for the ignition vacuum advance.



What you are describing over by the kickstart sounds like the crankcase vent. That needs to be filtered somehow also.

I do not have a vacuum port on #2 carb. i think the ignition vacuum advance works with four small hoses like this one:

http://s1188.photobucket.com/albums/...t=DSC03121.jpg
could that be possible?

[BA80]

Which pic are you talking about?

[bikerphil]

AFAIK, the XS11 is the only bike to use a vacuum advance so your Zuki carbs won't have a port. The bike should run ok without the vac advance.