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Discussion Starter #1
Ive been having trouble lately.While idling,the rpms will jump from about 1100rpm to about 1250rpms for about 3 seconds,then go back to 1100rpms.It sounds like one of the cylinders is not firing or getting gas.When I lean the bike to the right,while idling,the rpms go up.I can ride for about 13 miles ok,then all of a sudden,while in low gears,it starts wanting to die.I have to rev it up,to get home quick.It sounds like,blub,blub,blub,blub.I drained the carbs.The left side drained about a cup of gas.The right side drained about a 1/4 of a cup of gas.I could hear gas boiling or something on the left side.The gas tank vent was hissing.When I opened the gas cap,it made a noise like psssssssss.Alot of pressure in the tank.Also,I have noticed that the left carb will leak around the shaft that moves the butterfly valve or around the choke plunger.My quess, is that the valve seat on the float is not working.Stuck or whatever,letting gas just flow over.I just want to make sure that this problem is my carbs,#1 and not something else.Any help will be greatly appreciated. Steve
 

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Sounds like you have 2 problems, some carb issue and that your tank vent is blocked. Easy way to check the tank vent is to disconnect the vent hoses (under the seat, 2 small hoses at the base of the tank). Start up the bike, when it starts to sputter and wants to die, disconnect the hoses, if it starts running good again, then you have a blockage in the vent/evap system.

Safety tip: Don't leave these hoses disconnected as raw gas and gas fumes vents out of the tank into them (right above the rear cylinder exhaust manifold).
 

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HAWK
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Some tanks only have 1 hose on the tank. California bikes have 2.
 

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Once Banned
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Make sure after you getting everything back together that you check/change your oil. Just in case any of the flooding on that cylinder got past the rings and into the crankcase. But it sounds to me like you're on the right track.
 

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That is almost the same thing that happened to me... right after filling the tank.. blub, blub.. ran bad all the way home. after a trip to the dealer, it turned out to be a plugged vent hose.

All was good after that!! Check the little things first.

If you have an air compressor you can blow through the vent tubes to see if they are plugged.
 

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Unless I'm mistaken, it's the hose under the seat at the back of the tank. It's for emissions laws. Goes into an evaporative cannister.
 

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HAWK
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cegodsey said:
Unless I'm mistaken, it's the hose under the seat at the back of the tank. It's for emissions laws. Goes into an evaporative cannister.
Only goes to a canister on Clifornia bikes. Mine just hangs down in front of the swing arm. If I fill the tank and park in the sun it will drip out gas due to the heat. only 3 or 4 drops but I can see a spot on the ground
 

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Good! that explains the smell of gas I had after I parked it in the garage yesterday.
 

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Discussion Starter #10 (Edited)
carb questions

Does this hose connect to the petcock? or are the two lines from petcock just vacume lines to suck gas when engine is running? Does anyone have a picture of this fuel vent line? When I say,that I drained about a cup of gas out of the left carb,does that sound like a stuck float needle?how much gas is usually in the carb? Steve:baby:Also,my bike is an '86 with 21,000 miles.
 

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HAWK
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I agree with the sound of a stuck float, you should only get a couple of tablespoons from a carb. The petcock should have 3 lines on it, 1 vacume 2 fuel lines. The petcock is vacume operated, it will close when the motor shuts off when working right. The vent hose we are talking about is on the back of the tank under the seat. When you remove the seat you will see it just above the bolt that holds down the tank. If the tank vent is plugged the pressure could be opening the float, which could cause the flooding issue. or if it building a vacume and starving the one carb. Using it as a vent sucking air through it due to a stuck float.
Hope this helps
 

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Discussion Starter #12
Thanks Chad.I will check that out. I have 3 lines from the petcock.One line I thought was a fuel line,goes to a port beside the idle adjust knob.Then the other two hoses go underneath tank.
 

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HAWK
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The one that goes to the port you can see is the vacume. the other 2 are fuel.
 

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Discussion Starter #14
I think i put seafoam in the vacume lines.It smoked for about 3minutes,then quit smoking.
Is the vent line connected to the tank? or carbs?
 

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The tank vents are connected to the tank, just above and forward of the battery, underneath the seat. There may be one or two, depending on whether you have CA emissions or not.
 

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Discussion Starter #16
No hose on back of tank

I finally saw a pic of the tank vent hose.My '86 has no vent hose or hoses on the back of the tank.So do I pay attention to the gas cap vent?
 

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and the Adventure Cycle
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There were two different tanks for the '86.
The other has 2 hoses.
But how you described the different amounts of fuel you drained from the carbs seems funny.
You don't have the petcock at the 'PRI' position, do you ?

There is what's only desribed as an oil seal under the gas cap for Cali bikes.
It wouldn't hurt to clean the cap.
And an '86 w/ 21,000mi, carbs might need a good cleaning and possbly parts replaced.

Good luck Steve
 

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Discussion Starter #18
No fuel vent hose

After looking at pic's and consulting my local Kawasaki people, my bike doesnt have a vent hose at the base of the tank.My only vent,is the gas cap.I took it apart and cleaned it,so now it vents fine.There was a little rubber pink flap in there,that broke.Its venting fine,but I hope that flap will not cause further problems.It is the size of a small smilley face that we can use on this forum.Look here:BLAM:
 
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