Carb Vents Need Help???

[Redneck]

This morning I bring everything up and finish getting carbs all put together. That is when I notice something

Which one is not like the other one


Now I do have all the cross connections installed but three out of 4 have the vent ports coming out. When I tried to compare them to the other rack of carbs I have, those were completely different also. So I am completely confused. Some Help would be appreciated.

Here is a close up of the carb in question and of between two of the other ones.





Help!!!!

Paul

[7981GS]

The one with the broken piece of tubing on it is one of the two vent ports.
The other one, is for the petcock to draw vacuum from.

Daniel

[Redneck]

The one with the broken piece of tubing on it is one of the two vent ports.
The other one, is for the petcock to draw vacuum from.

Daniel

Just for clarification top close up is picture A and bottom is Picture B

In picture A you can see the Tee that will connect to the petcock and allow fuel to enter the carbuerators. There is no nipple on the side of the carb body in the picture above it

In picture B you can see the nipple coming out of the Carb body where there was none in picture A. This is the part that draws vacuum on the petcock. Does that mean I need to cap off the other ones and the ends that are open on the outside?

Paul

[7981GS]

Let me take some pic's of the carbs on my 550 and get back to you unless someone else wants to help first.

Daniel

[Redneck]

Thanks I do need the help.

Paul

[verde]

http://www.thegsresources.com/_forum/showthread.php?t=185443

That should help.

Edit, from one of the posts there, look inside and you can ID the one that is petcock vacuum. This is how it is on a set of 750 carbs:


And you can look for other clues like the fuel passages to make sure you didn't swap the order around. For instance #1 and #4 are easy to ID since you don't want fuel spilling out past the end of the carb rack:

[BassCliff]

Hi,

Maybe I'm just looking at it wrong but it seems carbs 2 and 3 are reversed. (Or is that not possible due to assembly requirements?) Note that I'm not a VM expert.

Thank you for your indulgence,

BassCliff

[verde]

In picture B you can see the nipple coming out of the Carb body where there was none in picture A. This is the part that draws vacuum on the petcock. Does that mean I need to cap off the other ones and the ends that are open on the outside?

Paul

Do not cap off any vents, the carbs need to breathe. Two carbs share one vent line, that's what the 1/2 inch piece of tube linking them is for. Do cap off the vac nipple if you are not running the standard petcock.

[verde]

Hi,

Maybe I'm just looking at it wrong but it seems carbs 2 and 3 are reversed. (Or is that not possible due to assembly requirements?) Note that I'm not a VM expert.

Thank you for your indulgence,

BassCliff

Yeah, it's along those lines. I'm guessing the #1 is in the #3 spot at this point, but I don't have any first hand with the 550, just that other thread. These VM racks can be incorrectly assembled in any order, vent and fuel passages being the subtleties between each.

[Redneck]

Hi,

Maybe I'm just looking at it wrong but it seems carbs 2 and 3 are reversed. (Or is that not possible due to assembly requirements?) Note that I'm not a VM expert.

Thank you for your indulgence,

BassCliff

Well for one I now have another setback. You were not totally wrong Basscliff, #3 is not the right carb body. That was the one with the messed up Pilot Screw I could not get out. I did not know about the Petcock vacuum port on the engine side till you just posted it. I went and looked and sure enough I did not have that hole. I went into the garage and looked through the other carb bodies and found the right one. Now I have to dip the body again, find a time I can sneak into the base and use the paint room, before I can progress.

Problem #2 is none of my Carb bodies look like this


They all go straight through which leads me to wonder if I need a plug on the ends of them also. or is the middle filled like it seems to be on one of them.

Does anyone have a good diagram for how these Carbs are suppose to work. Thanks.

Paul

[Pendulum]

It looks like you're missing your #3 carb. Looks like you've got #1 where #3 should be, and an extra #2. Did this rack of carbs come off a running bike? I'll try to get pictures of my carbs tonight. My bikes not at my house currently though, so not making any promises.

EDIT: These pictures are from my thread the verde linked to.

Here's what your #3 carb should look like:

[verde]

Problem #2 is none of my Carb bodies look like this


They all go straight through which leads me to wonder if I need a plug on the ends of them also. or is the middle filled like it seems to be on one of them.

Oh. You're mixing and matching carb racks. I can see using a middle carb for an outside position and plugging the fuel passage, but that just seems a little... redneck Are you sure you've got all middle carb bodies? The actual drilled hole between the fuel passages is kinda tiny and hard to see at the wrong angle. It starts at the tip of the arrow and only occupies that bottom half of that passage way pictured.

[verde]

Does anyone have a good diagram for how these Carbs are suppose to work. Thanks.

The picture from that old ebay listing in the other thread showed a carb rack in unmolested form. Maybe this will clear up the descriptions. 1&2 and 3&4 carb pairs need to have that short piece of hose linking them for venting purposes. Then the vent hoses from #2 and #4 nipples just need to be long enough to be routed to terminate in some calm air(over and behind the air box is the stock set-up I believe). Fuel passages need to be in the right configuration to allow fuel to all carbs(and not to flow out past the end of the carb rack as discussed already)

[BassCliff]

Hi,

OK. I thought something looked a little off. I guess Mr. Redneck needs to put all the proper carb bodies in the proper places in the rack. They are not interchangeable.


Thank you for your indulgence,

BassCliff

[Redneck]

Well thank you very much everyone. Not sure what happened to my last post from yesterday unless the Internet ate it prior to it posting, but here is the final lay out.

I had an issue with a getting out a pilot screw on one of the carb bodies, so after I stripped the top out I drilled it out and attempted to use an easy out. Of course when I attemp these things they never go the way I want and so the easy out snapped off clean inside the pilot screw further compounding the situation. Well instead of getting too upset and exploding all over the place I grabbed one of the carb bodies from the spare rack of carbs I had. Not really knowing as much as I do now. I dipped it painted it and transfered all the hardware over and we ended up with what you see in the above pictures. Which is

#2-#2-#1-#4

So yes I have (2) #2 carbs on the rack and the #1 is in the #3 Position.
Good news is I had to take the wife grocery shopping last night. I was a little peaved because I did not want to attempt to use the remaining carb dip since I just finished soaking my brake calipers in and it was kind of blackish ( by the way carb dip does pretty good job of stripping paint from Calipers). So while I was at the grocery store I picked up a bottle of pinesol. Got home took out an empty plastic coffee tub, stripped the correct carb body from the spare rack, and dropped it in the coffee tub full of pinesol and put on the lid. I will get it all cleaned up tomorrow night and try to have it painted by this weekend so that I can hopefully get those blessed carbs installed by the weekend.

Anyway thanks again for all the help.

Paul