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How To Remove Carb Assembly?

5K views 38 replies 7 participants last post by  ninjanut 
#1 ·
I need to remove the carburetor assembly for cleaning. I removed the choke cable per Clymer manual instructions and loosened the throttle pull/push cables. I also loosened all four clamp screws to the point of the clamps freewheeling. When I try to lift up the assembly it won't budge. The whole bike moves back instead. What's going on here? Any tricks before I just put the whole thing back together and tow it to a mechanic?
 
#5 ·
Pull straight up on the carb bowls. Not 90 degrees to the carbs, 90 degrees from the ground. Then pull straight back on the top of the carbs. As mentioned, don't go crazy. One hand on the front and back of the carbs. Pull one side at a time and rock them. They are a bitch in colder weather, and who knows when it was done last.

If you think this is hard, wait until you try to put them back on in the cold.
 
#6 ·
Pull straight up on the carb bowls. Not 90 degrees to the carbs, 90 degrees from the ground. Then pull straight back on the top of the carbs. As mentioned, don't go crazy. One hand on the front and back of the carbs.
I pumped several shots of engine fogging oil into the seams between the carbs and rubber boots, waited 15 minutes for it to work around the diameters, did this, and they popped right off.

Now I need to unscrew the float bowls and black plastic covers that are on top of the carbs. Somebody told me these are JIS screws and just want to confirm having already stripped out the screw holding the choke bracket onto the assembly. If I need to get a JIS screwdriver I'll do so instead of going through the nightmare of drilling stripped screws out with an extractor.
 
#7 · (Edited)
I found that taking a drill with a screwdriver bit works perfectly in removing the float bowl screws. Managed to strip only one by hand until figuring this out. Now I have two questions about cleaning:

A) The main jet on one carb thus far was coated in varnish that I cleaned off after soaking it in gasoline and noticed it has many tiny holes throughout the shaft. I picked them with a paperclip needle end. Is this enough or should I look for a smaller diameter needle?

B) Can somebody give me run-down of what the pilot screw does? According to the Clymer manual, on US models it is supposed to be plugged and hence non-adjustable. On my bike there are no plugs and I noticed the outer two are more or less perpendicular to the float bowls while the inner two carbs have them roughly parallel. Are their settings dependent on each carb's tuning or are they supposed to be in the same position throughout all four carburetors? Pic attached so you can see what I am referring to.
 

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#9 ·
A. The main jets are screwed into the emulsion tube which has tiny holes down its length. Main jet only has one hole down the middle. Careful picking at them with any metal object which is harder than brass as you may distort, scratch or damage the orafice. At that point you will have troubles getting them to run perfect.
B. The pilot screw will richen the mixture (counterclockwise) or lean the mixture (clockwise). Screw them in and count number of turns in 1/4 increments until GENTLY seated. That is what they are set at. Usually they are all set the same. Make sure when you remove them that you extract the washer, spring and o-ring that is in there as well.
They should all point up perpendicular to the bottom of the carb.
 
#12 ·
Regarding the pilot screws I found that carbs 1 and 2 were three full revolutions out from gently seated. Number 3 was 2 3/4 turns out and number 4 was just over three full turns out. According to the Clymer manual:

Initial pilot air screw setting for 1993-1995 ZX7 models
Austrian, German - 1 3/4 turns out
California, US, Swiss - Fixed, not adjustable
All others - 2 1/4 turns out


Do I meet in the middle and go two turns out? By the way, judging by the spark plugs the bike was running rather rich.
 
#17 · (Edited)
I got lucky and found them on ebay. They are 4x4.4mm shoulder bolts incase anyone else needs them. Since I am waiting for them to arrive I figure it is a good time to ask about this. When I took the air box off I found this pipe on the carb assembly just sitting there uncapped. Second pic is what was on the air box. Any idea what is going on here? I can't imagine the airbox should be drawing in unfiltered air like this. I looked on a Kawasaki parts diagram and could not make sense of it. The bike has the air injection (Clean Air) system but isn't a California model so it doesn't have the fuel vapor canister.
 

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#18 ·
I cleaned out the float bowls, main jets, and pilot jets from the varnish and then put the carb assembly back on and the bike still won't run. At best it will start for a second or two then die. Does not matter if I try starting it with the choke or no choke but throttle open at all. Any other ideas because I am out of them and ready to just put the tank and fairings back on and probably tow it to a mechanic in the spring. Fuel lines, fuel filter, and spark plugs are all new.
 
#19 ·
Starting issues will be the pilot jet circuit, mixture (pilot) screws and fuel level.
Is the fuel pump filling the bowls up to the correct level? When you cleaned the pilot jets, were they perfectly clear? When you reassembled the pilot screws, did you have the spring/washer/o-ring in correctly?
Did you blast out all the internal passages with carb cleaner and compressed air? If everything is not totally clean and clear, you will have issues. Ideally, I always ultrasonically clean carbs. You would be shocked to see what comes out of visibly clean carbs.
Also, how is the battery? Valve lash within specs?
 
#20 ·
Is the fuel pump filling the bowls up to the correct level?
All I know is that the bowls are filling up with fuel per cracking each drain plug.

When you cleaned the pilot jets, were they perfectly clear? When you reassembled the pilot screws, did you have the spring/washer/o-ring in correctly?
I got them as clean as I possibly could. The Cylmer manual said that carb cleaner is not recommended and so I used gasoline to clean them. I was very cautious when reassembling everything. I posted here about how the pilot screws were all three turns or more out and I set them all at 2.

Also, how is the battery? Valve lash within specs?
Battery is brand new and charged up to 13v. Did not check valve lash as I don't even know how. I should mention that the bike will backfire once in a while trying to start it. One loud popping noise like a gun going off.
 
#21 ·
I always clean them with ultrasonic cleaner followed by blasting passages with carb cleaner. Gasoline is not really going to clean carbs and passages. If it did all you would have to do is run it.
Check that you have strong spark at all four plugs. After trying to start it, remove one of the plugs and see if it is fouled and wet with fuel. Does it smell of gas when it doesn’t start? Could be the back firing is fuel building up and then igniting but getting drowned out.
 
#24 ·
What I meant is, make sure you have a fat blue spark on all four plugs. Ground them one at a time against the cylinder head to check. If they do not spark, you might have another issue (ie:grey wire...). Need to figure out if you have everything needed for combustion. Fuel mixture, compression and spark. Any of these missing and motor will not run. If you are sure that the carbs are providing mixture, assuming you have reasonable compression, that only leaves proper spark.
 
#25 ·
I tried starting the bike today and it will run consistently and smoothely with the choke at least 3/4ths engaged but will stall as soon as I shut the choke off. I am thinking the carbs need a second and better round of cleaning. What's this ultra sonic cleaner mentioned earlier? Also, any other tips on properly cleaning them? Such as what passages do I spray?
 
#28 ·
#26 ·
If it runs fine on choke but stops when choke is off, maybe just the idle screw backed out too far. Did you unscrew it when cleaning the carbs?
You were posting that it wouldn’t start. Now it will but won’t run without choke? Did you do anything to correct the no start?
 
#29 ·
Or,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

You cant get the stuff we used to that coined the phrase "boil out the carbs" so what I do now is , Get a crock pot add Dawn with water, using Berrymans or old school carb cleaner can have chemical reactions, especially with the plastic parts, although Dawn is on the low end of the harshness scale. Certainly less so than carb "dip" but still a good idea to keep an eye on it as it cooks. Dawn or what ever and cook them for a day or two.
Make sure you get all the small o rings out that are buried in the carb body, like the air mixture screws and take note where they went and get new ones. Get an electrical cord and use the single strands to do the small ports etc. Get a can or 2 of Carb Cleaner and shoot it into a shot glass, put the pilot and main jets and let them soak for a day. Put the tip on the carb cleaner can and start blasting out every port, then push the wire back in them and douche them out again. Rinse in hot water and blow them out 1 more time with a air compressor.
The Pilot Jet holes are small, like really small, Hold them up to a bright light, If you can see a dim glow in the center there clear, No visible light in the center they are plugged. Ive never been able to find a wire that will go through the center, So soak in carb cleaner and use air pressure to clear them out. Also I always screw the air / fuel mixture screws in all the way before I install the orings and count how many turns in until it bottoms out. With the orings in you will start feeling resistance and those screws and seats are very fragile. When you know how many turns in once the orings are installed you safely know how many more turns in is bottomed out.

Carbs are mechanical big time, there is not much to adjust, if all the ports are clear and clean they will work. when reassembling them use some oil on the o rings so nothing gets torn, Also the diaphragms will likely be all out of shape, so use some axle grease in the groves of the carb bodies to kinda glue the diaphragms in place so when you put the lids on they stay where they need to be.
Once you get the carbs all put back together with the bowls OFF but not on the bike, hook a hose to the fuel inlet that feeds all the carbs. flip the 4 carbs assembled upside down and blow air into the line.
You shouldn't be able to blow air through. Keep feeding air into the line and 1 carb at a time manually open each fuel valve and air should start coming thru, then close and no air flow. Do that for each carb and make adjustments to get all 4 working. Also when the carbs are upside down make sure the floats are all level.
Its a lot easier to get all this working off the bike.|

you can do it, piece of cake Bro !!!!
 
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