Hose Connection

Martin’s last pictures show there doesn’t appear to be any PAIR system installed (no chrome pipes from the exhaust manifold).... so... he can disregard all our discussion/pictures about that. :rolleyes:

I also think I see the #2 cylinder’s vacuum hose sticking up. So it seems the #4 cylinder’s hose has been inelegantly tapped into to provide vacuum for something.

Martin, let us know what the clear PVC hose is connected to. Thanks.

John
 
Martin Schneuer said:
FYI, may have already been covered in previous replies, but the picture below is consistent with the vacuum fuel valve bypass. That appears to be the #3 carb vacuum line that controls the vacuum fuel valve. When you do the bypass you block that vacuum line with a bolt or something similar.

.IMG_4356.jpg
Click to expand...
 
Today I found and spoke with the mechanic that assembled the Bikes when arrived to Chile. He told me that those ST came from England and is the Police Version.
After lunch I will visit the previous owner who found the topics and perhaps is together with the handles for the passenger.
During the weekend I will continue taking out plastics and miscellaneous and will take the filter out.
John, no doubt I will inform to what the clear PVC is connected and whatever I found. I saw the pictures of your motor and work. Looks better than new. Congratulations!!!
 
Hello John, Dale, Terry, Michael, Bush, Bikeric, Supra Sabre, fnmag, and DeanR.

Some issues are being clarified. Still have not taken out the carbs to find if the bike has PAIR valve…. and I have new doubts.
A summary is the following:
1) The yellow hose connects the cylinder vacuum hose # 4 (left rear) with the fuel cutting valve. See Photo 1
2) I found that the hose that I did not know where it was going should connect to the Air Filter housing. According to the service manual, the hose goes straight down. The 90º curve does not enter naturally. Any comment? See Photo 2
3) I found a loose hose under carb # 4. It was not connected to anything. See photo 3. It is probably related to the yellow hose in photo 1.
4) The O-ring of the filter cover was not installed.
5) The O-ring under the Air Filter Housing was not installed
6) The sub air cleaner (sponge) was not installed. Doubt: The bottom part of the sub air filter case does connect to anything? See photo 4
7) The hose that goes from the right-side plastic connector of carbs #1 and #3 to the sub air cleaner is bent and obstructed at the plastic outlet. I guess the plastic is turned pointing up so that the hose does not bend. The plastic has the letter L (Left?). Should it go to the left side of the bike between carburetors #2 and #4? See photo 5.
8) I have not found the carburetor drain tube.
9) Get to the carburetor assembly removal. I am following the service manual steps. I will remove the cable throttle when the assembly is lifted, since there is very little access to do as per manual.
I released the connecting band screw of the 4 carbs. Supposedly what follows is to lift the carburetor assembly, but I do some force and it does not move. I'll be grateful if you tell me if I'm missing something or there's some trick to get it out.

Best regards to all,
Martin
1.jpg2.jpg3.jpg4.jpg5.jpg
 
You need to pry the carbs off their boots, which are likely very dry and brittle rubber by now. On either the right or left side, use a broom handle to pry, being very careful not to be prying on any carb linkages.

Pulling the fuel tank gives better access to the throttle cable and is easy to do, but be sure to disconnect the wires to the fuel gauge sensor on the left side of the tank, partially hidden by the frame.
 
With regards to the sub air filter - It has probably disintegrated years ago and was never replaced. It is a very thin, porous piece of foam, meant to keep large particles from finding their way into the carbs. The problem with not paying attention to that filter is that when the foam disintegrates over time, it and any accumulated dirt get into the carbs and can cause damage to the carb diaphragms.

The hoses on the sub filter housing go into each side of the carbs at that plastic piece in your 5th pic. There is nothing else attached below the housing itself. Don't know about the "L" on the plastic, as both sides should have that plastic part.
 
RE: The sub air filter- I replaced mine with a lawnmower filter that was 2 pieces of mesh with the filter media in between (I think I bought it at Lowes for < $10)- anyway, I cut it to size and that’s what’s in place of the foam filter now- mine was in one piece when opened, but did disintegrate in my fingers trying to pull it up.
 
I can not identify (getting old?) the 4 new carb boots. Somebody can tell me the number and link of a part list diagram? Thanks in advance.
 
Also, the Honda fiche organization isn't always intuitive.

The carb boots are under "left cylinder head" and "right cylinder head" but they have the same part number on each fiche.

The elbows and a few other hoses are under "water pipe" (which for many of us held an entirely different meaning in our teenage years.)

The other stuff is under "radiator"
 
I took out the carburator assy of my ST 1100. The bike does not have PAIR system and any evaporative system.
I have now the following questions and I hope the forum wise members will help me clarifying it:

1) Where to take vacuum for the Cut-off valve?
Regarding the doubt of the yellow hose vacuum that was connected to the fuel cut-off valve, how it was installed came from cylinder #4 carburetor (see picture 1).
I believe the following (without knowing the bike):
a) The yellow hose was installed to replace the hose that that fall off when I took the carb assy out (picture 2).
b) The fuel cut-off valve must be connected to vacuum somewhere. The plastic T could be a connection to cylinder #4 carb, the second end to the fuel cut-off valve and the third end to a hose with a plug for carb synchronization as it was installed, ….. or the other option is that the T connects cylinders #2 and #4 vacuum hoses and the third end goes to the fuel cut-off valve. For carb synchronization you unplug the T.
But for both options I wonder if the vacuum to the fuel cut-off valve has influence in the carb synchronization.
Any other option?

2) Rubber engine heat guard bellow carb assy is needed?
No rubber engine heat guard was installed. All version needs that heat guard? Since is an expensive part, it can be cut from a simple rubber sheet or a special heat resistance sheet should be used?

3) Air breather to air filter?
The breather hose that connects to the air filter goes somewhere? See hose 11 at picture 3.jpg. I thought it was connected to the motor somewhere, but I could not find where to connect it. Help please.

4) Carb drainage connection?
The carb drainage shown in picture 4.jpg connects at the right-side lower part of the motor as shown in picture 5.jpg. Is that correct? Could be possible that the breather hose of point 3 connects in point shown in picture 5.jpg and the drainage hose goes straight down to the atmosphere?

5) Vent Hose?
The vent hose shown in picture 6 was not installed in my bike. It is needed?
1.jpg2.jpg3.jpg4.jpg5.jpg6.jpg
 
1. vacuum for cut-off valve comes from #3 cylinder. Not sure if the hose in picture two could be that hose or not, if its the correct diameter and its long enough then I'd use it. then connect #2 and #4 back together with a Tee, but I'm not sure where the 3rd leg of the Tee connects, perhaps someone else can answer that question.

2. don't know, perhaps others can comment on how necessary that mat really is.

3. the breather hose that connects to the airbox is a twisted odd looking hose that connects to a nipple on the water pump at the front of the engine as I recall. I think your second-to-last picture shows the bottom end of that hose, but I could be mistaken. See item #1 on the "water pump" fiche to see the breather hose.

4. carb drainage hoses go to left side of bike and hang loose, they're not attached to anything on the other end. I've only been in there once so my memory is weak on how they attach to the carbs.

5. that's just an air vent to flow cool air to the fuel shutoff valve, don't know if is really necessary. the one in the picture isn't your bike?? Bypass/remove the valve then that hose becomes unnecessary.
 
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1 - the darn T confused us from the start. Throw it away along with the clear PVC hose. Plug the #4 vacuum hose. No need to connect the two left side vacuum hoses together. Connect the #3 vacuum hose to the Auto Fuel Valve (vacuum petcock).

2 - I’d sure install the mat, and yes, you can make your own, others have. There are pictures in my album of how it looks. Don’t want to boil the carb float bowls gas in hot running.

3 - the crankcase breather hose runs from the right front of the engine (nipple on the lower right edge of water pump housing) up and into the V of the engine to the nipple on the bottom right side of the air cleaner housing.

4 - the individual carb float bowl hoses connect to the 5-port drain hose manifold shown in your picture. The larger hose from the manifold leads straight out the rear of the engine V to a butt connector to a hose extension that drops down and to the left side around the alternator through two wire routing bails and ends with two other drain hoses (fuel splash tray and fuel cap vent) just inside the lower fairing by the riders left foot. If you drain the carbs this where you catch the drained fuel. Here’s a shot of the hose leading out from the V: http://www.st-riders.net/coppermine/displayimage.php?album=38&pid=1139#top_display_media

5 - keep the hose. It provides cool air to not only the Auto Fuel Valve but also, more importantly, to the air intake at the rear of the airbox. Some ST1100 have another tube on the other side also. Mine didn’t so I bought the parts and installed it.

HTH

John
 
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Thanks dwalby and John for your replies.
John, your instructions are clear. If I follow what you stated in point 4, which hose goes to te motor exit (right lower side) 5.jpg shown in the following picture?
 
Martin, the hose and connection in that picture is the crankcase breather hose connected to the nipple on the water pump housing. My point 3 answer. I had to take a good look at your picture and then my ST1100 in the cold garage in order to figure it out. My 1991 is the only year and model that doesn’t have the crankcase vent through the water pump housing like that. The metal tube yours leads into also threw me.

John
 
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