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Carb connecting hose

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25 Apr 2023 07:13 #883723 by SRQ Mike
Carb connecting hose was created by SRQ Mike
Recently I had my carbs cleaned by a local shop I've used in the past.  I reinstalled the carbs.  Since then I've had an issue with 
the number two and three carbs not functioning properly.  This morning I discovered the small connecting hose between the number two and three carbs
is not connected properly. (see picture) It appears that I will have to remove the carbs (again) to correct this issue.  My question is: What kind of gas flow problems
would be caused by this hose not being connected properly?  Would it affect the gas flow to the number two and three cylinders?   Thanks for your help.  

 

1979 Kawasaki KZ650 SR

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25 Apr 2023 07:20 #883724 by Mikaw
Replied by Mikaw on topic Carb connecting hose
That’s a vent to help balance atmospheric pressure between carbs. Just an FYI that can’t be between 2&3 carbs. It can only be between 1&2 or 3&4. Your problem is more likely the open vacuum brass nipple on carb number 2 rear in your picture. That should feed vacuum to your Petcock.

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
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25 Apr 2023 07:51 #883726 by SRQ Mike
Replied by SRQ Mike on topic Carb connecting hose
My mistake.  It is between 1 and 2.   The gas tank of off.  That's why the vacuum line is not connected.  

1979 Kawasaki KZ650 SR

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25 Apr 2023 07:58 #883729 by Mikaw
Replied by Mikaw on topic Carb connecting hose
What symptoms are you experiencing. That vent won’t cause any problems. If you could use a rounded blunt tool and push the hose back into position it will work as designed. 

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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25 Apr 2023 10:36 - 25 Apr 2023 14:17 #883735 by SRQ Mike
Replied by SRQ Mike on topic Carb connecting hose
The symptoms are that the engine is running on cylinders one and four.  I'm getting spark on all four cylinders but the gas flow is questionable.  (plugs do not appear wet).
What's odd to me is that it seems to run very smoothly on one and four.   Is it possible that it's actually running on all four cylinders?  The number two and three exhaust pipes are not hot at all.  

1979 Kawasaki KZ650 SR
Last edit: 25 Apr 2023 14:17 by SRQ Mike.

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25 Apr 2023 15:01 - 25 Apr 2023 15:08 #883744 by hardrockminer
Replied by hardrockminer on topic Carb connecting hose
If those are #1 and #2 carbs...are the fuel/air screws facing each other?  The carb on the left (#1 I think) looks to have the fuel/air screw facing inwards.  If so then at least two of the carbs are mounted incorrectly on the face plate.  If you look at the carbs carefully you can see ports on either side for the fuel Tee connection.  But only one side on each carb is open to the float valve.  The other side is sealed off.  

Edited to add that each carb has a specific position on the face plate.  They are not interchangeable.

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
Last edit: 25 Apr 2023 15:08 by hardrockminer.

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25 Apr 2023 16:22 #883754 by hardrockminer
Replied by hardrockminer on topic Carb connecting hose
I have a couple of sets of 24's so I went to check them just to be sure.  The fuel Tee is in the middle, between 2 and 3.  There are connections between 1 and 2 and between 3 and 4.  So 2 and 3 have fuel inlet/outlet on both sides, not just one as I mentioned above.  1 and 4 have one access to the float valve.  The other one is sealed.

As mentioned above, each carb has a unique position on the face plate.  Can you confirm they are all in the correct place?  A couple of photos of the carbs would be useful.

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.

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25 Apr 2023 16:39 #883757 by Mikaw
Replied by Mikaw on topic Carb connecting hose
If plugs 2&3 are dry, the either they are firing or they are not getting fuel. Do you have an inferred thermal temp gun? An inductive timing light is a quick way to test if a plug if firing. Also 2&3 are fired by the same coil, you can test voltage at the coil primary terminal. 

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.

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25 Apr 2023 17:28 #883760 by SRQ Mike
Replied by SRQ Mike on topic Carb connecting hose
The coil for cylinders 2& 3 was cracked, so I replaced it.  I borrowed a infrared heat gun and the number 2 & 3 exhaust read around 90.  (This is in Florida).   I'm attaching pictures of all four carbs.  Let me know if you see something which might cause the problem.   It's puzzling because the engine runs very smoothly.  (I temporarily moved the air intake springs back in preparation of removing the carbs)

 

1979 Kawasaki KZ650 SR
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26 Apr 2023 05:08 #883776 by hardrockminer
Replied by hardrockminer on topic Carb connecting hose
The carbs look to be properly mounted on the faceplate so fuel to the carbs should be correct.  

You say you have spark on all cylinders, so the ignition system should be functioning correctly.  Otherwise I might suspect a problem with the timing pickup or with the igniter.

Normal fuel flow is into the T between 2 and 3 and then from 2 to 1 and from 3 to 4.  If 1 and 4 are running normally it suggests fuel is getting to them correctly.  The problem may be with the internals on 2 and 3.  Can you check via the bowl drain to see if you are getting gas into the bowls?  

I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
The following user(s) said Thank You: SRQ Mike

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27 Apr 2023 08:26 #883835 by SRQ Mike
Replied by SRQ Mike on topic Carb connecting hose
After further checking it appears that the carbs are way too rich.  I pulled the plug wires on number one and four and it turns out that two and three will run, but not very well.  The plugs are very dark/black.  So,  I'm going to lean them up a bit and see what happens.  Thanks for all your help.  

1979 Kawasaki KZ650 SR

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27 Apr 2023 15:18 #883853 by Mikaw
Replied by Mikaw on topic Carb connecting hose
I didn’t get a chance to reply but I noticed #2 carb air pilot looked turned in a bunch more than #1. That would make #2 richer than #1. Turn them all in lightly seated and back out about 1 1/4 turns. Start the bike and adjust pilots for best idle. You can clean up the plugs with a propane torch. Or buy new. Either should be done before the next start/tune

1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
The following user(s) said Thank You: SRQ Mike

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