Kawasaki Ninja ZX Forum banner
1 - 18 of 18 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Before you ask, i have already researched this forum and others.

I recently bought this bike and ran it for about 2 weeks with no problems. I then decided to paint it, while everything was removed I did the plugs and oil along with an oil filter and k&n air filter. After reassembling it started fine and the next day on my way to work it made it 3 miles and died like it ran out of gas. So I put some more gas and still no luck. I now have the fuel tank set up externally. It will run and start fine at this point below 4-6k rpm. But anywhere above that it will bogg and die. It will also die if I snap the throttle. Maybe not enough fuel at the higher rpms? I've cleaned the fuel tank and fuel filter along with the fuel selector. Any ideas would be greatly appreciated.

Thanks,
Ty
 

·
Banned
Joined
·
3,608 Posts
Look down the carbs and make sure there isnt fuel flowing out of the slide needles.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #6 ·
Hey guys,

After some more tinkering I'm beginning to think I'm not getting enough fuel at the higher rpms or under load. Is there a way I can check that my fuel pump is pushing enough fuel? I know these aren't super high volume pumps but it will sputter and die once it gets to 5k. If I back off as soon as it starts to sputter it will idle fine again. Any ideas?
 

·
Registered
Joined
·
80 Posts
from the looks of it you can buy a new one on ebay for a hole 60 bucks so a lil trial and error wouldn't be to bad... did you check the fuel filter and make sure it was completely clean?
 

·
Premium Member
Joined
·
11,231 Posts
Fuel pump shouldn't have much or anything to do with fueling at those RPMs, all it does is keep the bowls filled. If it works, then it is not the problem.

Clean the shit out of everything in the carbs. If you put in a K&N and didn't adjust for it, then your bike might just be too lean up top.
 

·
Premium Member
Joined
·
11,231 Posts
So make sure the carbs are spotless, and all four slides are moving freely.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #11 ·
Another thing I noticed is that its pushing air out the intake when it Boggs down like in the video. Any ideas why that would happen?
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #12 ·
Right before the video I put everything back together after cleaning the carbs. The slides check out as well.
 

·
Premium Member
Joined
·
11,231 Posts
Pushing air OUT the intake? Like back up through the carbs? Are you sure its coming out and not just fuel/air mix being sprayed about from the action of the slides?

Mine makes a bit of a "mess" like that.

If yours is actually blowing shit out, then either your valves are fucked, or the timing is fucked.

But it probably wouldn't even idle in that case.
 

·
Registered
Joined
·
2 Posts
Just to add to this thread.

I had the EXACT same problem. I could upload a video of nearly the same response to throttle engagements. The difference, however, was how I fixed my problem.

Here's a little backstory.
Bought the bike in November 2013 with a seized engine. Screw inside cylinder 4 and 3 valves bent throughout the head. Replaced rings, gaskets, valves, and seals. Put it all back together and fired right up.
The bike came with an aftermarket Leo Vince slip-on and a jet kit installed.
Pilots are 40's across all four carbs.
Mains are 172 on carb 1-4 and 175 on 2-3.
Float heights were 4.25mm +-.25mm
(Stock pilots are 38's, mains 160-165, and float heights 4mm)
I adjusted my float heights down to 2.5 on all four and almost completely eliminated my bogging above 5k rpm's.
My own explanation of why is that the float heights, not being adjusted, caused a lack fuel to be drawn through the larger jets prematurely emptying the bowls past the point where the amount of fuel needed exceeded the amount of fuel available.
In addition. I had cleaned the carbs THOROUGHLY several times while making several needle adjustments (adjustable needles were part of the jet kit I assume) all to no avail.
I hope this helps.
 

·
Banned
Joined
·
3,608 Posts
It is definitely a carb issue. Pull them off, and clean them all. main jets and everything, then make sure the float height is set to 14mm as a starting point. You are running out of fuel in the top and or the slides aren't coming up.
 

·
Premium Member
Joined
·
2,530 Posts
Are all of the hoses to the ram air and the air box hooked back up correctly? If they are not put back correct, it may display the condition you describe of bogging at higher revs.
 

·
Banned
Joined
·
3,608 Posts
It will only do that while the bike is moving. Stationary, it should matter as long as the air box adapter is on.
 

·
Registered
Joined
·
498 Posts
That sounds to me like the slides aren't coming up when the butterflies open. Do you have good vacuum at the diaphrams? There are two quick ways to tell. First, lift each slide with your finger and let it drop. You should hear a "vacuumy" noise as it descends, and it should descend a little slower than if it simply fell. You can also blow into that large port above the carb mouth. A breath of air should easily make the slide pop up.

Heck with the airbox off you should be able to see the slides start to rise as you roll on the throttle. Do it slowly and see if they are coming up.
 
1 - 18 of 18 Posts
Top