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1982 CB650SC carb cleaning

Posted: Sun Jul 16, 2017 8:45 pm
by Hutch1
I noticed when cleaning the carbs there are tubes between carbs 1 & 2, and 3 & 4 visible from the choke plate side that have holes in the middle (see pics). I can't figure out what this tubes/parts are on the part diagram, can anyone shed some light? Is this normal or do these have to be replaced?
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Image

Re: 1982 CB650SC carb cleaning

Posted: Sun Jul 16, 2017 8:52 pm
by Hutch1
Pics...

Re: 1982 CB650SC carb cleaning

Posted: Mon Jul 17, 2017 9:01 am
by Folsoml
Those tubes are vents. Where you see the holes should actually be T fittings with a hoses coming off of them. Those hoses go over the top of the airbox. They do not connect to anything. You should replace them, as the carbs may leak if you do not.

Re: 1982 CB650SC carb cleaning

Posted: Mon Jul 17, 2017 5:02 pm
by Hutch1
Thanks Folsom!

Re: 1982 CB650SC carb cleaning

Posted: Tue Jul 18, 2017 7:58 pm
by Hutch1
Does anyone know the part number, it was difficult to tell from the diagram. I think it might be 16031469004 fuel joint set.

Re: 1982 CB650SC carb cleaning

Posted: Wed Jul 19, 2017 4:56 am
by Folsoml
Hutch1 wrote:Does anyone know the part number, it was difficult to tell from the diagram. I think it might be 16031469004 fuel joint set.


That's just one of the the small aluminum fuel pipe that connects the carb banks. What you want is this:

http://www.partzilla.com/parts/detail/h ... 0-771.html

Re: 1982 CB650SC carb cleaning

Posted: Wed Jul 19, 2017 6:37 pm
by Hutch1
Seems pricey for what should be a $3 part, but at least they are available.

Re: 1982 CB650SC carb cleaning

Posted: Sun Aug 27, 2017 4:24 pm
by Hutch1
Folsoml wrote:Those tubes are vents. Where you see the holes should actually be T fittings with a hoses coming off of them. Those hoses go over the top of the airbox. They do not connect to anything. You should replace them, as the carbs may leak if you do not.


I think I found the tee fitting part number (16047460771), however, I can't find a vendor online that stocks the part. Does anyone know where I can source the part, or if there in an off-the-shelf alternative?

Re: 1982 CB650SC carb cleaning

Posted: Sun Aug 27, 2017 4:51 pm
by Folsoml
It shows as available here. Did you try and find they were out of stock?

http://www.partzilla.com/parts/detail/h ... 0-771.html

Re: 1982 CB650SC carb cleaning

Posted: Sun Aug 27, 2017 9:07 pm
by Hutch1
I would say that's my bad :oops: I was clicking on the usual parts sites, and so used to seeing "out of stock" that I missed the fact they were available on partzilla.

Re: 1982 CB650SC carb cleaning

Posted: Sun Aug 27, 2017 9:16 pm
by Hutch1
On a new note, I have a new tank without the vacuum-assisted petcock. I'm trying to figure out what to cap off on the carbs since I don't have a vacuum-assisted petcock. I can't seem to locate the "vacuum tit" as the McGrogor manual calls it, am I missing something????

Re: 1982 CB650SC carb cleaning

Posted: Mon Aug 28, 2017 5:43 am
by Folsoml
There should be a brass nipple on carb #2.

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Re: 1982 CB650SC carb cleaning

Posted: Mon Aug 28, 2017 9:15 pm
by Hutch1
My carbs are a bit different. I found 2 brass numbs, one on the accelerator pump.
0828172138.jpg
0828172138.jpg (1.17 MiB) Viewed 10739 times

The other is on carb 3 in the same location as the drain screws on 1,2 & 4.
0828172137.jpg
0828172137.jpg (1.2 MiB) Viewed 10739 times

That numb was connected with a hose to the underside of the accelerator pump to the hose barb circled in red.
0828172136a.jpg
0828172136a.jpg (1.03 MiB) Viewed 10739 times

Re: 1982 CB650SC carb cleaning

Posted: Tue Aug 29, 2017 4:47 am
by cb650
that is not the accl pump. it is the auto fuel shut off. Accel pump is part of #2 bowl.

Re: 1982 CB650SC carb cleaning

Posted: Tue Aug 29, 2017 3:28 pm
by Hutch1
cb650 wrote:that is not the accl pump. it is the auto fuel shut off. Accel pump is part of #2 bowl.


Wow... I really need to take the time to understand how the carbs work! So I'm guessing the brass nipple that screws directly into the carb body on the bowl side is the one that needs to be capped?