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**XS1100_OEM4ME** · 08-27-2010, 02:08 AM

Wtf

WTF, please attach some photo's of your carbs, not some cyber link, we can help but need to see "real photo's" could be bastard carbs, could be wrong lines

. Please let us help you with "your carb photo's"

**Alan1982XJ** · 08-27-2010, 03:00 AM

I see and hear of people talking about bypassing the OCTY on their bikes by linking all the lines together like this, still feeding them from the respective pet-cocks.

Does this actually do any good for the bike?

**XS1100_OEM4ME** · 08-27-2010, 03:29 AM

Octy

Originally posted by Alan1982XJ View Post

I see and hear of people talking about bypassing the OCTY on their bikes by linking all the lines together like this, still feeding them from the respective pet-cocks.

Does this actually do any good for the bike?

Dont know your bike as you dont have it in your singnuture

Will speak from a 79 special. 1st the petcocks have 4 pos. on,off, res, prime. If you plum the on, res, to a "T" from both sides then to the two carb feeds, block off the "prime" feed at the petcock it will work (line filter would be good) You will have to turn off the petcock when not running and when you turn it on it will "prime" the carbs with no octy, good luck with your bike

I would keep the octy

**Alan1982XJ** · 08-27-2010, 04:30 AM

Yeah, I have no desire to do this to my bike as I simply don't see any performance boost to doing so, was just curious what it did exactly and what was being seeked out by doing it.

82 XJ1100 btw

**b1lock** · 08-27-2010, 06:01 AM

My bike is a 80 special. A couple of summers ago the octy started leaking while on a ride a long way from home. Using what I had with me on the side of the road, I plugged the vacuum inlet on the intakes. Then I connected the two front outlets off the petcocks with a crossover hose. Then I ran fuel lines from the back outlet pipes to the inlet pipes on the carbs. My bike runs the same as before without the leaks from the octy and I don't shut off my fuel when I park. Make sure your carbs are in good order so they don't flood when parked. I don't see any advantage to removing the octy unless it is leaking. Bob

**natemoen** · 08-27-2010, 06:43 AM

Originally posted by daneglerum View Post

Hi Guys,

I've been reading through the forums trying to find an answer but it just isn't clicking for me.

I'm putting the carbs on to my XS and wanting to hook up the fuel lines.

When I look at the carbs it seems that I have fuel intakes between 1 & 2 plus 3 & 4 . I understand this is normal and assuming I want to bypass the octy (I DO) I just route these up to 'rear' output on the petcocks.

The issue I have is that my carbs also appear to have an inlet between 2 & 3.

This has a pipe coming of with a T.

Here is a rough drawing. http://screencast.com/t/MjE1NDk1Y

From this I have 2 questions;

1. Can I just group all the hoses together and run them to the petcock (similar to this: http://screencast.com/t/NzNkMWQyMW ) or should I block the tube between 2 & 3?

2. What other hoses need to be connected to the carbs in order for the bike to start.

Apologies for my total stupidity with all things mechanical!

I would say you might want to take the carbs off and investigate this a little more. My guess is some previous owner has messed some things up. You might have carbs from several different bike or they could just be mixed up. The carbs have a hole on either side of them where a fuel or a vent line could be hooked up BUT depending on where the carb sits in the rack the hole was not fully drilled through the carb body so there is still aluminum blocking it. So there should be nothing hooked up to the left side of carbs 1 and 3 and nothing hooked up to the right side of carbs 2 and 4. All connections are in between 1 and 2 and then between 3 and 4.

As said before some good pictures of the carbs and the places where the fuel lines are connected would help immensely! But my suggestion would be to pull the carbs off and figure out what is really behind those Ts on the carbs. It might be that someone just switched 2 and 3 and put a fuel line there so they could still run it that way (although it would take more than that to really make it work).

Just for fun. There is a black hose that should come from the lower left side of the engine behind the cover that says Yamaha on it (its the timing advance cover) that hose should run up to the carbs and it should hook up to a little brass nipple on the #2 carb BODY (not the black intake boot). If that little brass nipple is on the #2 carb then the carbs are probably in the right place, but there should only be that brass nipple on the #2 carb and no others.

Keep us informed, I am kinda curious here. Hopefully I helped a little. Good Luck

and what year and model XS do you have?

**Larrym** · 08-27-2010, 11:28 AM

A Missing link?

daneglerum,

I second natemoen's version of that "2-to-3" connection/Tee. The carb bodies have the port there for a Fuel tee to fit inside but usually it's a blind/dead end hole. If that's the case then that additional Tee might be just ornamental.

With that being said....PO's can sometimes get "creative". Possible that the PO got out his drillbits and put a hole there to accomplish some sort of "Fuel Level Equalization" or an "Improvement" above and beyond what the Yamaha/Mikuni engineers in their white lab coats could fathom.

How very interesting!!! Maybe an undocumented Breakthrough that will soon be discussed/appreciated in detail and then added to the Tech Tips as the Mod that achieves ?????

Practically, I'd say that it would be safer to assume that the Tee is "Active" in some fashion either as a fuel vent or as fuel delivery at least until you can confirm otherwise. I mean that the "usual" orientation and position of the carbs requires the usual Tees positioned between 1+2 and 3+4. Maybe this is a way that the PO used to Mix/Match the carb bodies he had available to the positions he needed to put them in.

(or at the very minimum the PO found a convenient way to store/carry a spare fuel/vent Tee along with extra fuel line. Ever try to get one of those things when you're OTR and stranded somewhere????

)

**fredintoon** · 08-27-2010, 12:27 PM

Originally posted by daneglerum View Post

Hi Guys,
- - - I'm putting the carbs on to my XS and wanting to hook up the fuel lines. - - -
When I look at the carbs it seems that I have fuel intakes between 1 & 2 plus 3 & 4 . I understand this is normal and assuming I want to bypass the octy (I DO) I just route these up to 'rear' output on the petcocks.
The issue I have is that my carbs also appear to have an inlet between 2 & 3.
This has a pipe coming of with a T. - - -

Hi Dan,
if your Australian '80 is plumbed like my Canadian '80 Special, the T between #2 & #3 carbs is an orphan.
I'd cap it or plug the holes.
My octopus valve was long gone when I got the bike.
It ran with both petcocks turned to "on" or "reserve" and had the "prime" fuel spigots plugged and leftside petcock connected to rightside tee and vice-versa to allow space to fit in-line fuel filters.
And Alan,
running without the octo is simpler, is all. The octo is OK until it acts up but anything that uses 9 hoses where 2 would do has to be a disaster waiting to happen.
Just gotta remember to turn the fuel off when you stop and turn it on again to start. If you can't do that you shouldn't be riding.

**daneglerum** · 08-28-2010, 05:24 PM

Thanks for all the help guys! I'll get some photos of the bike today and the more details.

I can confirm that the lines are all linked. Eg if I connect the lines between 12 34 then fuel comes out of the mystery tube.

I'm thinking that it could well be that the Aussie bike is the same as the Canadian. Or the PO has attempted some magic.

Once again, thanks for the help. I'll have a detailed look today and take some photos.

**fredintoon** · 08-28-2010, 05:39 PM

Originally posted by daneglerum View Post

- - - I can confirm that the lines are all linked. Eg if I connect the lines between 12 34 then fuel comes out of the mystery tube.
I'm thinking that it could well be that the Aussie bike is the same as the Canadian. Or the PO has attempted some magic. - - -

Hi Dan,
not my Canadian bike. 1 & 2 are Teed together as are 3 & 4 and that's it.
2 has a cast-in blind bore on it's right side & 3 has a cast-in blind bore on it's left side.
I suppose they could be machined out to fit a Tee between them and I'd suppose that's what some PO did to yours.

**petejw** · 08-28-2010, 06:01 PM

the aussie bikes arent to much different from
the bikes overseas, and none of the models
have the carbs linked the way you have yours linked.
what model have you got?

and on a side note,
are you aware that theres an aussie xs site,
heres a link

http://xs1100.com.au/forum/index.php?action=unread

if you need a hand with anything drop me a pm.

**daneglerum** · 08-28-2010, 08:05 PM

Ah. It would seem that I am in fact an idiot. I've had another look the carbs and things are a bit different. I've also taken photos but will need the computer to upload them.

The line between 12 and 34 feed into the carbs quite high. Whilst the T one between 23 feeds in about inline with the centre of the carb.

So perhaps these are bastard carbs. Although the bike was running at one stage with these on.

So now I'm really confused as to what is fuel in etc. Any ideas?

**petejw** · 08-28-2010, 08:23 PM

sounds like u have the early model carbs,
the top 'T's are float bowl vents and either
need to be attached to the air box or just vented,
dnt block these off as it will result in flooding the carbs,
the bottom 'T's are for fuel.

whats the start of ur vin no: so we know what model
your wrking with.

**natemoen** · 08-28-2010, 08:24 PM

The pics will be the best help for all of us here.

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Fuel Intake between carb 2&3

Fuel Intake between carb 2&3

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