Kawasaki Ninja ZX-6R Forum banner

1 - 20 of 29 Posts

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #1 ·
Greetings bike fiends and friendly mechanics,

Bought a 2000 zx6r j1 not long ago and its had this problem ever since i got it.
It runs fine until the tank starts getting low, then it dies as if out of fuel. If i top it up it works fine again. Same thing everytime.
I can hear a hissing sound from gas cap when i shake the tank. Opening the cap doesnt help.
Things i have tried:
-Removed and cleaned the gas cap. (real puzzle to put back together!).
-Drained tank, no water, no rust and seems very clean inside (only very few tiny sparkly particles).
-Removed petcock and cleaned filters. Found a tiny fly. bzz.
- New air filter, fuel filter, cleaned coolant filter, coolant flush.
-Checked fuel pump, seems to work fine.
-Adjusted valves, were way off.
-New oil, filter and spark plugs.
-Installed a new gas cap (vortex 3).
-Removed carbs, cleaned, new gaskets and float valves. Diaphragms seem fine. Float height adjusted (Not 100% sure i did height right, but shouldnt be the issue). Fuel screws 3,5 turns out (have tried 3, and 2,5). Synced carbs with homemade glass bottle setup.
-New gaskets in and under air box.

None of this has helped. Feels like something is clogged. But where do i clean? And how?
Is the petcock the culprit or is there something wrong witht the tank itself? Could it be an air leak?|
Hope someone can help. Im a total beginner, got the bike before winter and spent the cold months learning from forums and youtube.
Appreciate your time, thanks.
 

·
Registered
Joined
·
14,219 Posts
If the lower portion of the tank is unusable, that typically means there is gunk blocking the fuel pickup.
 

·
Registered
Joined
·
14,219 Posts
The pump sucks in fuel from nearly the bottom of the tank... nearly the bottom so it doesn't have to deal with sediment and rust. There is a particle filter at the pump intake to protect it from garbage in the fuel. If the tank was left to evaporate all of the fuel out of it at some point, the lighter part of the fuel will -- and the thicker stuff doesn't. When nothing is left that can evaporate the gummy stuff that is left behind dries into an impenetrable layer of stuff.

Along you come, and pour in fresh gas. That new gas will flow through the part of the filter screen that didn't get plugged up with that dried up stuff.... when the level drops to lower than that goop nothing gets to the pump.

There should be a number of threads on this site discussing how to take the pump apart and replace the filter that Kawasaki does not want you to replace.
 

·
Registered
Joined
·
8,798 Posts
^ NO......

This is a carbureted bike with a standalone fuel pump and still has a traditional fuel petcock.......

Sounds like your fuel pump is on its last leg and when ypou have a full tank or even 1/2 or more of a full tank the head pressure is enough to push past the pump and keep the carbs full...... (you can pull the pump all together and it'll do this exact same thing, run fine as long as you never let the fule level get below about 1/2-5/8 tank)

buy a new fuel pump and install.. 99% certain that fixes your problem (otherwise test fuel pump pressure and flow with a full tank and with one that is leass than 1/2 and see the difference yourself..- if different replace the fuel pump)

fyi........ fuel level in the float bowls makes a big difference in jetting, set it near the high end or at the high end the variance allowed in the spec sheet...... 9mm/9.5mm I believe off the top my head
 

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #6 ·
I actually did order a backup ebay pump a while ago. The wire connector doesn't fit though. I gave up on thinking a new pump would fix it because i tried bypassing the fuel pump and that didn't fix the problem.
But it might have been stupid to think gravity fed would be better than a bad pump.
Maybe i should just dish out for an oem one as i hear ebay ones are crap anyway.
Thanks alot for the feedback.
Might have saved me alot of time looking for dirt that doesn't exist.

Oh and i actually did set the floats a bit high. Manual says 7+- 2mm. Put calipers on 7mm but gave the floats a bit of room to compress so they would seal properly when i press the calipers down to measure 7mm. So maybe 8 or 9mm in reality. They seem about parallel with the carb when i turn the carbs and let them drop.
 

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #7 ·
^ NO......

This is a carbureted bike with a standalone fuel pump and still has a traditional fuel petcock.......

Sounds like your fuel pump is on its last leg and when ypou have a full tank or even 1/2 or more of a full tank the head pressure is enough to push past the pump and keep the carbs full...... (you can pull the pump all together and it'll do this exact same thing, run fine as long as you never let the fule level get below about 1/2-5/8 tank)

buy a new fuel pump and install.. 99% certain that fixes your problem (otherwise test fuel pump pressure and flow with a full tank and with one that is leass than 1/2 and see the difference yourself..- if different replace the fuel pump)

fyi........ fuel level in the float bowls makes a big difference in jetting, set it near the high end or at the high end the variance allowed in the spec sheet...... 9mm/9.5mm I believe off the top my head
So the fuel pump finally arrives and i install it thinking we all good. But today i barely made it home from work... same problem at half a tank. It started bogging on the highway just 2 mins from home. It died right after cruising down the exit and i just rolled down to my garage.
Im starting to think this might be electrical? Not enough juice to the pump?
But the tank does make a woosh/hiss until I open the cap. It then stops and starts again if i close the cap and shake the tank. Cap off wont help with starting it as i stated before. So not sure how relevant this woosh noise is.
What else could it be?
Starting to lose faith. If anyone got any ideas id be real happy.
 

·
Registered
Joined
·
8,798 Posts
So, is the vent line plugged so the bike is cavitating? you should not be getting a great deal of "vacuum" as fuel level lowers and it sounds like what you describe is the tank getting vacuum
 

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #9 ·
So, is the vent line plugged so the bike is cavitating? you should not be getting a great deal of "vacuum" as fuel level lowers and it sounds like what you describe is the tank getting vacuum
Yes my first suspicion was vacuum. But from what i can tell there is no blockage.
There is one line coming out from the tank that runs under the seat. This is an overflow/vent line if i am not mistaken. Should there be more lines than that? Why would anyone plug a vent line, and how do i know if its plugged?
 

·
Registered
2021 Kawasaki ZX6R 636 KRT ABS
Joined
·
120 Posts
I had this exact problem on my 1985 Honda 250 3 wheeler and it was a vacuum problem. I ended up drilling small holes in the gas cap. Probably not the same issue since you stated that opening the gas cap doesn't resolve the problem but it sure does sound like the same issue. At half a tank there shouldn't be any issues with a clogged petcock.

So the only way to get going is to fill the tank up with gas? Try driving with the cap open to rule out a vacuum problem.
 

·
Registered
Joined
·
8,798 Posts
Yes my first suspicion was vacuum. But from what i can tell there is no blockage.
There is one line coming out from the tank that runs under the seat. This is an overflow/vent line if i am not mistaken. Should there be more lines than that? Why would anyone plug a vent line, and how do i know if its plugged?
You should have atleast two........ (some of the CA have 3)

one is a solid metal line through the tank and to the cap area to drain any water or fuel spill above the cap sealing surface and has an outlet spigot of rubber hose that would normally go somewhere close to the ground
the other is also a slid metal tube through the tank but stays inside the tank under the cap and again has a rubber hose attached going somewhere close to the ground (or to a carbon filter box if a CA model)- the only difference between the two.......one is a vent for fuel level to lower and the other is a drain for anything caught under the fuel cap but above the caps sealing washer
 

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #12 ·
I had this exact problem on my 1985 Honda 250 3 wheeler and it was a vacuum problem. I ended up drilling small holes in the gas cap. Probably not the same issue since you stated that opening the gas cap doesn't resolve the problem but it sure does sound like the same issue. At half a tank there shouldn't be any issues with a clogged petcock.

So the only way to get going is to fill the tank up with gas? Try driving with the cap open to rule out a vacuum problem.
Yes the bike wont start unless i fill it back up. Well one time it happened i managed to get it going (BARELY) by keeping the choke on. Didnt get far hehe.
I have tried opening the gas cap but that doesnt help with starting it once the fuel is low.
I only have 10 liters to burn, then it stops. Its not the end of the world, but can be tricky since there is no fuel meter.
 

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #13 ·
You should have atleast two........ (some of the CA have 3)

one is a solid metal line through the tank and to the cap area to drain any water or fuel spill above the cap sealing surface and has an outlet spigot of rubber hose that would normally go somewhere close to the ground
the other is also a slid metal tube through the tank but stays inside the tank under the cap and again has a rubber hose attached going somewhere close to the ground (or to a carbon filter box if a CA model)- the only difference between the two.......one is a vent for fuel level to lower and the other is a drain for anything caught under the fuel cap but above the caps sealing washer
108324
108325

This is all thats coming out of the tank other than the fuel line thats below.
I imagine that if there were more lines they should come out the same place?
Does this tell you anything?
 

·
Registered
Joined
·
8,798 Posts
If there is not another one under the tank anywhere..... either;

they combine somewhere inside the tank to only have one exit
or
the cap is the actual vent

Do you still have the oem original cap or an aftermarket cap?
 

·
Registered
Zx6r 2000 j1
Joined
·
21 Posts
Discussion Starter · #15 ·
If there is not another one under the tank anywhere..... either;

they combine somewhere inside the tank to only have one exit
or
the cap is the actual vent

Do you still have the oem original cap or an aftermarket cap?
I currently have a Vortex v3 cap installed. I thought the oem might cause the issue. Still have the oem tho. Seems it makes no difference. First thing i did was disassemble the oem cap and clean it. Didnt help so i bought the vortex.
There's nothing else coming out of the tank but that one rubber hose leading to the ground. And the fuel line ofc.
Its a j1 2000 zx6r europe model.
 

·
Registered
Joined
·
8,798 Posts
I'd have to think the interior of the one vent line you do have is clogged, somewhere.
Well one is just a drain from overflow up top and one is a vent, but it seems they exit the same hole/hose at the back of the tank???

try blowing some compressed air (not a ton) through the hose and put your finger over the obvious top drain to block that and see if air still moves through the actual vent line


or a vacuum may be easier on the system, or blow with your mouth.......
 

·
Registered
Joined
·
14,219 Posts
I'm in the camp of the vent line is clogged; we seem to all be in agreement that the situation resides within the plumbing on the tank...... what happens if you ride the bike with the rubber hose disconnected from the tank? It's possible the rubber hose is pinched somewhere; that's pretty low hanging fruit, and should have already been checked, but I haven't seen that box ticked yet.

Yes, if the inside of the metallic tube has gotten rusty enough to be clogged getting a solid core fine wire that is only slightly smaller OD than the ID of the pipe would be the first step in trying to clear out the obstruction. Aluminum wire, or possibly brass would be my suggestion....
 

·
Registered
Joined
·
8,798 Posts
How would i go about unclogging that?
Empty the tank and stick something long and thin through the vent hole i presume?
Sounds like a PITA!
You would not even have to empty the tank.......... start with just blowing some compressed air in there and see if it comes through the other side, or blows anything out

I have seen many of these inside the tank vents tube crack or rust through then fuel comes straight out (when the crack is below fuel level)
So if you are going to shove anything through make sure it is soft and flexible- like air would be........ You could safely put 20psi in there..... I have blown spider nests out of some and they were so dense it took nearly 40psi- but it was sketchy and as thin walled as those tubes are I doubt they are rated for 40psi
I have also split a couple open trying this when they took near 40psi and still nothing happened til it did- the lines split open and whatever the clog was- remained above the split.......

So it is high risk is what I am saying.........

one other thing maybe doubtfully but maybe...........

Just drain the tank and pull the petcock completely out....look and see if someone somehow for some reason added length to the pick ups, or fucked it up in some way shape or form............. free and easy enough to do

and as mentioned above, simply remove the rubber line and make sure it is free and clear of obstruction or kinks.....
 
1 - 20 of 29 Posts
Top