Kawasaki Ninja ZX-6R Forum banner
1 - 20 of 29 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter · #1 ·
My 1995 bike has all these weird tubes from the carbs and the airbox and the vacuum system which I think are part of the ram air system.

There's a 'valve' which is a lot like a fuel valve in that it's actuated from a vacuum line from a carb boot
from what I can tell it links the hose from the top of the airbox through to the carb vents when the engine is running.

IS this part of ram air, like is it trying to alter the pressure above the diaphragms as the pressure in the airbox changes?

Or is a system to vent the carb bowls either to air, or to a catch can (california) or back to the airbox when there's a vacuum there to draw vapor in.

Long story short, the previous owner of the bike has lost the hose from the top of the airbox to the valve thing and I'm trying to work out if I can delete all this crap, block off the airbox hole and be done, or will I hurt my carb performance?
 

·
Registered
2002 AP1 636
Joined
·
28 Posts
Can't really answer your questionive got a 2002 I'm rebuilding at the minute into a track day bike but the engine is back in and I'm also wondering about all this 'extra crap' for the air intake
 

·
Registered
Joined
·
525 Posts
Reading all of your post it looks like your mixing the EVAP & Ram Air systems thinking their one of the same, There not.
You need the Ram Air but you can junk the EVAP system by carrying out a Evap Delete.
 

·
Registered
2002 AP1 636
Joined
·
28 Posts
Reading all of your post it looks like your mixing the EVAP & Ram Air systems thinking their one of the same, There not.
You need the Ram Air but you can junk the EVAP system by carrying out a Evap Delete.
Hi KevA,

sorry to OP to cut in here but just wondering about what you’ve said here.
So on my old 1190R I did a ‘canister-ectomy’ for the charcoal canister and other emissions crap. Do the really old bikes (mines 2002) have anything I can junk whilst rebuilding it?
 

·
Registered
Joined
·
525 Posts
I assume your 2002 is a ZX636 A1P ?
You can remove all the EVAP Crap, I'll put together some images in a bit and post them to this #7

So you can remove everything in the first Image, Cap where the Blue Circled is removed, Cap the underside of the Air Box where Green Circle fits onto, Red Circles attach to the EVAP Plates in Image 2 the Top one with the Black cross through it (Discard the Bottom Crossed one at the same time) this is done for both sides.
You then need to fit what they call Block Off Plates, 3rd Image, These are sourced from E-Bay and this set offers the Air Box Bung and 1 Carb inlet bung, Link HERE







Ask if your not sure (y)
 

·
Registered
Joined
·
27 Posts
Discussion Starter · #8 ·
Right, so ignoring the MASSIVE thread steal that's going on here :D
The lower half of the rubbish can go, (which is a bit annoying in that the upper half clips onto the lower half.) but the upper lot that connects to the TOP of the airbox IS balancing the carbs to the pressure in the air box to make the venturi work correctly?

Not that any of us actually know how any of it works at all :) So I need to build a hose out of a right angle and a straight bit and some joining bits which is annoying, but oh well.
 

·
Registered
Joined
·
9,525 Posts
Bicycle handlebar Bicycle tire Automotive lighting Motor vehicle Automotive tire

you can remove the pair valve and accompanying hoses as stated......

the ram air itself and the idiotically stupid aluminum body valve (above the rag in the picture) you need to keep unless you are going to reinvent the wheel and try and convert to the better system used on the J models........

the carb bowls absolutely need to be pressurized to work and that is what pressurizes them from the pressurized air box
 

·
Registered
2002 AP1 636
Joined
·
28 Posts
I assume your 2002 is a ZX636 A1P ? YEP

So you can remove everything in the first Image, Cap where the Blue Circled is removed, Cap the underside of the Air Box where Green Circle fits onto, Red Circles attach to the EVAP Plates in Image 2 the Top one with the Black cross through it (Discard the Bottom Crossed one at the same time)
Hi KevA,

Wow, brilliant description and pictures. Much appreciated! I've ordered the block-off plates so they will be down for the weekend I hope. I have done the same job to a few bikes I've had in the past but this is the first (proper) bike with carbs I've owned not counting my old XR125.

Thanks again and I'll give you a shout if I have questions if that's alright?

And a question to you @riverszzr . The picture you've attached there with all the carbs in a vacuum state. That is only possible or stable because of the aluminium valve you mention?

I've just put in a new fuel pump and filter and fuel hoses etc. and got her started without the airbox and other .. stuff. keen to get her purring properly but she seems okay at the minute. Might take a video and post it in a thread on my build progress, let me know what you think but probably difficult to tell on sound alone.. I'll get a carb balancer although I've no idea what I'm doing haha :rolleyes: oh well only one way to learn!
 

·
Registered
Joined
·
745 Posts
And a question to you @riverszzr . The picture you've attached there with all the carbs in a vacuum state. That is only possible or stable because of the aluminium valve you mention?
The bike will start and run with the airbox and vent lines removed for carb balancing because it is not moving. What happens on the road is that the air intakes become pressurized due to the air flow forcing air in (slightly, it's not a huge effect at road speeds). Carbs work based on the pressure difference between the vacuum in the intake runners and the airbox feeding into the carbs. If the carb float bowls are not vented to the airbox/ram air pressure it screws up the fuel flow into the engine. My 98 will hardly run beyond about 50kmh with the vent line unhooked and it bucks and surges horribly at that speed. Reattach the vent line and it runs perfect again.

What the aluminum valve is doing is making sure the carb float bowls are properly vented to work correctly.


Mark
 

·
Registered
Joined
·
9,525 Posts
The bike will start and run with the airbox and vent lines removed for carb balancing because it is not moving. What happens on the road is that the air intakes become pressurized due to the air flow forcing air in (slightly, it's not a huge effect at road speeds). Carbs work based on the pressure difference between the vacuum in the intake runners and the airbox feeding into the carbs. If the carb float bowls are not vented to the airbox/ram air pressure it screws up the fuel flow into the engine. My 98 will hardly run beyond about 50kmh with the vent line unhooked and it bucks and surges horribly at that speed. Reattach the vent line and it runs perfect again.

What the aluminum valve is doing is making sure the carb float bowls are properly vented to work correctly.


Mark
Mostly accurate......

that aluminum valve body is actually making sure the float bowls are pressurized (not vented) to work properly at everything above perhaps 40mph......... they can be vented below that speed and work ok

people who develop cracks in the feed tube or other leaks in the bowl pressurization system oftem find out the bike runs fine to something south of 50mph then just falls flat on its face with no power at 50 and up.......... that would be in the vent only scenario of the float bowl

So yes you can synchronize them without any of the bulshit attached, you can even run them at low speeds without any of the bullshit attached
 
  • Like
Reactions: Mr Winston and KevA

·
Registered
Joined
·
27 Posts
Discussion Starter · #14 ·
I managed to snag an OG tube and spare valve for a decent price, so hopefully my bowls will be correctly pressured in the future. What's the value actually for why not just connect the airbox to the carbs? is it so that the over pressure can ONLY happen above certain vacuum levels?
 

·
Registered
Joined
·
745 Posts
that aluminum valve body is actually making sure the float bowls are pressurized (not vented) to work properly at everything above perhaps 40mph......... they can be vented below that speed and work ok
This is just semantics. If you vent to a higher pressure region it pressurizes the float bowls, but I would still call it venting. It's not really a vent line at all, it is a signal line to keep the bowls at whatever the reference pressure is. Where is the valve getting the higher pressure air from?


What's the value actually for why not just connect the airbox to the carbs? is it so that the over pressure can ONLY happen above certain vacuum levels?
That is a good question, because my 98 G model just connects the vent line to near the front of the ram air tubes, it doesn't have that valve at all if I'm remembering the intake plumbing correctly from a couple years ago.


Mark
 

·
Registered
2002 AP1 636
Joined
·
28 Posts
View attachment 112707
you can remove the pair valve (what is this?) and accompanying hoses as stated......

the ram air itself and the idiotically stupid aluminum body valve (above the rag in the picture) (above the rag or the thing with the rag stuffed into it?) you need to keep unless you are going to reinvent the wheel and try and convert to the better system used on the J models........

the carb bowls absolutely need to be pressurized to work and that is what pressurizes them from the pressurized air box
@riverszzr

thanks for your info and picture here.
I’ve added some questions to your response in green.
Am I correct in saying that I need to keep the top half of the below?
Automotive lighting Motor vehicle Vehicle Fender Automotive tire


If so.. WTF.. I’ve fit the block off plates. Which is were those two ‘arms’ plugged into on the top of the cam cover. Then the smaller pipe went the the top of the two middle carbs that 1&4 have a small pipe of same diameter but they are already blocked off. So that is odd.. if it’s needed?
Just a bit confused because the bottom part connects to a pipe that comes out from the bottom/side of the air box..

Can’t test it atm, just waiting for brake fluid bottle and then I can do a shakedown.

I don’t have the other aluminium thing you made reference too in your reply and the first guy said I could get rid of everything in the first pic..

Just a bit confused to be honest.

Hope someone can help clear things up a bit for me
 

·
Registered
2002 AP1 636
Joined
·
28 Posts
Just in an effort to further explain with pictures. The smaller diameter pipe on the top of the now removed.. plastic tree thing. Went to a T piece that split to the top of throttle bodies 2&3.

1 & 4 were not joined to the same T piece as they were already blocked as below.

Automotive tire Automotive lighting Rim Gas Automotive wheel system

Motor vehicle Automotive lighting Bicycle handlebar Bicycle part Vehicle








Now what I am curious about is the below.

Tire Wheel Automotive tire Motor vehicle Automotive lighting


This little splitter collects air from the front of the bike and brings it down a pipe thusly >

Hood Motor vehicle Automotive exterior Automotive tire Vehicle


So down here and it flows the the top of the carbs. down a common rail to each one. Here is each side of the pipe. First from the right hand side looking down to the end and then from the left side of the bike looking at the end of the pipe.
Automotive design Automotive tire Motor vehicle Automotive lighting Gas

Automotive tire Gas Auto part Automotive wheel system Tints and shades


So that pipe is bringing air.. is that the 'Ram air' system? Can't imagine it rams much air. although perhaps that isn't the point. Perhaps flowing just some air at a different pressure is exactly what it does?

Hope that makes sense. If not, please let me know what pictures I could take to further explain my confusion.

Note, the bike starts fine and drives in first gear okay at the moment. No front brakes yet so a faster shakedown will have to wait.
 

·
Registered
Joined
·
9,525 Posts
Just in an effort to further explain with pictures. The smaller diameter pipe on the top of the now removed.. plastic tree thing. Went to a T piece that split to the top of throttle bodies 2&3.

1 & 4 were not joined to the same T piece as they were already blocked as below.

View attachment 112841
View attachment 112840







Now what I am curious about is the below.

View attachment 112843

This little splitter collects air from the front of the bike and brings it down a pipe thusly >

View attachment 112845

So down here and it flows the the top of the carbs. down a common rail to each one. Here is each side of the pipe. First from the right hand side looking down to the end and then from the left side of the bike looking at the end of the pipe.
View attachment 112844
View attachment 112842

So that pipe is bringing air.. is that the 'Ram air' system? Can't imagine it rams much air. although perhaps that isn't the point. Perhaps flowing just some air at a different pressure is exactly what it does?

Hope that makes sense. If not, please let me know what pictures I could take to further explain my confusion.

Note, the bike starts fine and drives in first gear okay at the moment. No front brakes yet so a faster shakedown will have to wait.
That there is the system that pressurizes the float bowls.......... make sure that plastic pipe that is the junction to the 4 individual carbs is nont cracked (I have seen dozens of them cracked over the years)


from your post #17..........

yes that can be removed, just make sure the vacuumn line is plugged and the air box hole is also plugged
 
  • Like
Reactions: Mr Winston

·
Registered
2002 AP1 636
Joined
·
28 Posts
That there is the system that pressurizes the float bowls.......... make sure that plastic pipe that is the junction to the 4 individual carbs is nont cracked (I have seen dozens of them cracked over the years)


from your post #17..........

yes that can be removed, just make sure the vacuumn line is plugged and the air box hole is also plugged
Wow, now that is some response time. I feel like I should be paying a monthly subscription 😅

Okay brilliant! I've plugged the line from the airbox but I plugged it at the end of the hose because I knew I'd lose the hose if I plugged it further up at first so I will ping the hose off tonight and move my plug up right to the underside of the airbox. I will also give the hose a good check for cracks!

She's coming together nicely. Would you happen to know how the throttle cables are routed? I realise I am off-topic here and have asked the question in my build thread Here but just on the off chance.

I feel a lot more chilled now going forward, thanks for the help, much appreciated.
 
1 - 20 of 29 Posts
Top