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Feb 10th 2018, 06:50 PM   #1
 wadester33's Avatar
 
  Jan 2018
  portland

  99 VZ 800 marauder
question about c/v carbs

I've got a 99 vz800,what I'm wondering is about the fuel feed,the second carb is fed from a line coming out of the first carb,,now with the bike running if I pull that fuel line off the second carb,should there be fuel spraying out the line,,or does it rely on vacuum to pull the fuel into the second carb,,because right now if I pull that line I got nothing coming out

Edited by wadester33 on Feb 10th 2018 at 06:52 PM Reason: they are mikuni carbs also,,if it helps
Feb 10th 2018, 07:11 PM   #2
 unicykle's Avatar
 
  Sep 2017
  milwaukie oregon

  gsxr600 gsxr750 gsxr1000 i like gsxrs
Quote:
Originally Posted by wadester33
I've got a 99 vz800,what I'm wondering is about the fuel feed,the second carb is fed from a line coming out of the first carb,,now with the bike running if I pull that fuel line off the second carb,should there be fuel spraying out the line,,or does it rely on vacuum to pull the fuel into the second carb,,because right now if I pull that line I got nothing coming out
Usualy the carbs are gravity feed from the tank and each carb has a needle valve controled By the float in the float bowl to control the fuel level in each carb so i would say yes it should have fuel lighly pouring out in a stream. Im assuming you have a running issue not mentioned and arnt just playing with the carb

Also each float bowl usualy has a drain plug you can loosen to see if a carb is dry and not getting fuel, you can capture the fuel that comes out ( if any)and roughly measure the ammount that comes out of each bowl. The jets are high in the float bowl so there needs to be enough fuel in the bowl for the jets to suck fuel

Edited by unicykle on Feb 10th 2018 at 07:38 PM
Feb 10th 2018, 11:33 PM   #3
 wadester33's Avatar
 
  Jan 2018
  portland

  99 VZ 800 marauder
yeah I do,my front cylinder doesn't want to fire..so then I have a blockage in my no.1 carb,,maybe i'll see what a little compressed air will do
Feb 11th 2018, 05:38 AM   #4
 MMcN49's Avatar
 
  Jan 2016
  Small Island Surrounded by Puget Sound

  07 Buell XB12STT, (Two) 12 Suzuki DR650 SE 72BMWR75/5 KIA @ 243K
Quote:
Originally Posted by wadester33
yeah I do,my front cylinder doesn't want to fire..so then I have a blockage in my no.1 carb,,maybe i'll see what a little compressed air will do
Maybe, be careful with the compressed air. Looking at pictures of both carbs on the internet it appears that the feed hose for the second carb is rubber.

I have a 72 Beemer. When they started adding Ethanol the stock rubber fuel hoses would get gooey and start oozing fuel after awhile.

I think step one is to remove the hose and see what shape its in. If the carb hoses are all rubber and do not say Ethanol Resistant you should consider replacing them. Tygon seems to work pretty good.

https://www.processsystems.saint-gob...bing?id=251406

Ethanol also broke down the Beemers CV carbs o-rings and diaphragms over time. You may also need to replace your seals and diaphragms as well, (not really a big job). Try to find an Ethanol resistant seal kit or purchase o-rings made of Viton, not Neoprene or Buna N.

Below is a short video on CV carbs.

Feb 11th 2018, 05:48 AM   #5
 MMcN49's Avatar
 
  Jan 2016
  Small Island Surrounded by Puget Sound

  07 Buell XB12STT, (Two) 12 Suzuki DR650 SE 72BMWR75/5 KIA @ 243K
Additionally the Beemers floats were not alcohol resistant and have to be replaced every year or two.
Feb 11th 2018, 05:49 AM   #6
 
  Feb 2017
  Deming

  Gsxr600
Has the bike been sitting for a period of time?
Might just need to clean the carbs? Just a thought.
Feb 11th 2018, 06:37 AM   #7
 Jackaldj1's Avatar
 
  Jan 2016
  Port Orchard, Wa

  '03 Suzuki Marauder
I know that my '03 VZ800 has a fuel pump on the right side under the seat, behind the cover. As for getting fuel, I had to pull both carbs, take them apart and clean them thoroughly before I was able to get them balance correctly.
Also, you said it had a stage 1 kit with stock exhaust before, if I remember correctly. I had to upgrade my air filters and exhaust for higher flow when I did my stage 1 upgrade, I put K&N filters with a set of Cobra slip ons to get the flow needed for the increased flow through the carbs.
Do you have a copy of the actual Suzuki Service manual? If you want, I have a pdf version I could email you, I downloaded it off of a link from the MIG forum.
Feb 11th 2018, 07:20 AM   #8
 unicykle's Avatar
 
  Sep 2017
  milwaukie oregon

  gsxr600 gsxr750 gsxr1000 i like gsxrs
Quote:
Originally Posted by wadester33
yeah I do,my front cylinder doesn't want to fire..so then I have a blockage in my no.1 carb,,maybe i'll see what a little compressed air will do
Here are some pretty easy options
First you need to verify if the carb has fuel or not. the needle valves on the float have a rubber tip that if it doesnt seal lets too much fuel thru and fouls the plug and the plug will be wet and clean after running usualy after setting a day will run ok for a few secconds then drop the cylinder.

Ethenol does destroy most rubber after a year or two eapecialy if you let it sit for a period of time.

I wouldnt recomend compressed air i would recomend pull the fuel lines off the carbs and make sure you get fuel out both fuel supply lines if not remove rubber lines and blow thru with your lungs and check for deteriation/ blockage.

Removing carbs is pretty easy than take the float bowl off, manualy lift the float and blow into the fuel line and make sure the needle valve seals when float is up and lets air thru when its down. Then remove drift pin for float and remove float and needle valve. Unscrew the jets one at a time ( flat scredriver) and then used compressed air to clean the jet and carb passage and do all 3. Re assemble

Edited by unicykle on Feb 11th 2018 at 07:42 AM
Feb 11th 2018, 08:01 AM   #9
 curve addict's Avatar
 
  Apr 2016
  Des Moines, WA

  ...1987 Yamaha FZR1000...
Quote:
Originally Posted by wadester33
I've got a 99 vz800,what I'm wondering is about the fuel feed,the second carb is fed from a line coming out of the first carb,,now with the bike running if I pull that fuel line off the second carb,should there be fuel spraying out the line,,or does it rely on vacuum to pull the fuel into the second carb,,because right now if I pull that line I got nothing coming out
I have worked on a number of VZs. Yes, you should have fuel pouring from the hose.
Has the bike been sitting a lot?

I recommend never blowing compressed air through an assembled carburetor. Crazy things can happen, like crushed floats.

I suggest a full disassembly of both carbs and rebuild/replace the fuel pump.
Feb 12th 2018, 12:25 AM   #10
 wadester33's Avatar
 
  Jan 2018
  portland

  99 VZ 800 marauder
Hey thank you guys for the replies, no it hasn't been sitting long, I ride it every chance I get, I did pull the fuel line from the second carb,and blew in it and nothing, so like an idiot gave it a little suck and mouth full of gas, so there's gas there, but for what ever reason its not making it into the no2 carb.The fuel pump is brand new, the fuel line didn't look deteriorated or feel that way,so I guess i'll pull the carbs
Feb 12th 2018, 04:54 AM   #11
 MMcN49's Avatar
 
  Jan 2016
  Small Island Surrounded by Puget Sound

  07 Buell XB12STT, (Two) 12 Suzuki DR650 SE 72BMWR75/5 KIA @ 243K
Quote:
Originally Posted by wadester33
I did pull the fuel line from the second carb,and blew in it and nothing, so like an idiot gave it a little suck and mouth full of gas, so there's gas there, but for what ever reason its not making it into the no2 carb. the fuel line didn't look deteriorated or feel that way,so I guess i'll pull the carbs
You blew through the fuel line and nothing came out but when you sucked on it you got a mouthful of gas.

Sounds like somethings up with the hose. Before getting into the Nuclear Physics of pulling the carbs apart put a known good piece of hose in and see what happens. For a quick test you can use anything that seals.
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