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so i just bought a 93 for pretty cheap for some reason i just love the 93-99 900rr ive always wanted one so i grabbed this one, it runs but wont hold idle, its got a 919 motor in it where i dont know if its a hornet or a 900rr motor but the main things is that on the carbs there is a tube that runs in to the rack twice then runs off to the right side iam guessing it has to do something with the needles but it isnt connected to anything also where the line plugs into the gas tank it isnt taking fuel in i kind of knew what i was getting myself into but i just wanted to have this to build. Seeing everything that i have had has been injected this is something different i was wondering if any one can give me some input on how these line are suppose to run would really help.
 

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That line doesn't connect to anything nor does it activate the needles. The hose is only an air vent tube. It allows the carb bowls and slides to vent. As I have posted in your other thread the needles are controled by vacuum when the engine is running. Plus the bike should idle even with out the needles in the carbs. Factory Pro tested this and found that the bike would idle at or below suggested manufacturers set idle without the needles. If the bike won't idle then you need to make sure that the idle is set correctly first of all. This is done with the knob that is on the left hand side of the bike just below the gas tank. Turn it clockwise until the bike idles at 1200 rpm. If after trying to adjust this setting the bike still doesn't idle then there is a few other things it could be. Most likely though you have a clogged idle circuit. Did the carbs sit for a long time with fuel in them? If so the carbs are probably varnished. You can try buying some seafoam carb cleaner and running it through the bike. This will work if the carbs are not to bad. If they are really gummed up you will have to take them apart and clean them. I would suggest pulling the carbs off and removing the bowls. Then you will know if they are clean or not. If they are clean and in good working order then I would suggest checking to make sure that the idle screws are set properly.
 

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ok i did pull the cabrs off and clean the bowl and as many of the jets as possible, i did not see any adjustment screws though. I couldnt even find where to hook up the sync tool. i did get it to run but it will not idle unless i turn the throttle a lil bit. It still runs really rough like it isnt firing on a cylinder so iam going to see what i can do with the coils. Who ever had it spliced in the common ground and then just hooked the other two wires regularly. Oh yea the carbs were cleaned but sat for another six months so i went ahead and cleaned them also could the diaphrams cause this problem ?? i did take the top half apart and i didnt find any holes in them so...I kind of think its 1 of two things coils or carbs let me know what you think thanks:D
 

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If you mean the line that runs across the top of the carbs in that photo, that's the vacuum line to the fuel tap.
 

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i did not see any adjustment screws though. I couldnt even find where to hook up the sync tool. i did get it to run but it will not idle unless i turn the throttle a lil bit.
also could the diaphrams cause this problem ??
The mixture screws might be plugged to prevent you adjusting them but they should be in the bottom of the carb bodies.
Carb synchronisation should be off the intake manifolds or via plugs in the head itself.
If it only idles with throttle then wind the idle adjuster up a bit.
If you don't have the vacuum line connected to the fuel tap though, it'll be sucking air so won't idle well anyway.
The vacuum diaphrams shouldn't have any effect at all on idle.
 

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the air adjustment(pilot screw adjustment) screws on each carb is located right behind the rubber boot on the bottom each carb.if there has been a jet kit put in it won't look like a screw BTW, you will have to have a special "D" socket to do any adjusting and the "screw" is recessed in a collar of the body of the carburetor. if you have a mechanics mirror, that will help you alot to see this pilot adjustment screw. for the pilot screw- lightly seat it and then turn it counterclockwise 3/4 - 1 full turn out, make the same adjustment to each carburetor. there is no pre-set adjustment for the idle adjustment screw,so if you are having to twist the throttle a bit to get it to idle. just turn the idle adjustment screw in until you can get the bike to idle on its own at about 1,100 rpm. and as far as where to put the sync vacum guage its the allen head bolts right in front of the rubber boots on the engine side. the No. 3 carb won't have this allen head because its the base carburator and it cannot be adjusted.
 

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If you mean the line that runs across the top of the carbs in that photo, that's the vacuum line to the fuel tap.
The line across the top of the carbs in the photo is the air vent tube. The vacuum line for the fuel tap hooks up to one of the intake runners on the head.
 

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The line across the top of the carbs in the photo is the air vent tube. The vacuum line for the fuel tap hooks up to one of the intake runners on the head.
You can draw vacuum from several places.
According to the fiche though, that hose connects to the fuel tap diaphram.
I agree that it does seem strange to draw vacuum from all four carbs like that though.
 

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You can draw vacuum from several places.
According to the fiche though, that hose connects to the fuel tap diaphram.
I agree that it does seem strange to draw vacuum from all four carbs like that though.
That diagram is for a a 93. He said he has a 93 with a 919 in it. Which means that the motor is not out of a 93 it has to be a 96 or newer. I have a 919 and this hose is not for the the fuel tap.
 

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That diagram is for a a 93. He said he has a 93 with a 919 in it. Which means that the motor is not out of a 93 it has to be a 96 or newer. I have a 919 and this hose is not for the the fuel tap.
The hoses in the fiche are exactly the same from '93 through to '99.
Why would the carbs not be '93?
 

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The hoses in the fiche are exactly the same from '93 through to '99.
Why would the carbs not be '93?
All I know is that i have two sets of these carbs in my garage that I am rebuilding and jetting on my bench right now and they both have this hose. They are air vent tubes if they came off of a 919 motor if they came off of a 93 then your diagram would be right. I am guessing that he has a mixed bag of parts on this bike and that we are going to need to see more pictures and info about the bike to help properly. If you need to see a diagram from my service manual I can post one. It clearly list this hose as a air vent tube.

As for the carbs not being 93 I myself would have not put 93 carbs on a 96 or newer motor but that is just me.
 

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All I know is that i have two sets of these carbs in my garage that I am rebuilding and jetting on my bench right now and they both have this hose. They are air vent tubes if they came off of a 919 motor if they came off of a 93 then your diagram would be right. I am guessing that he has a mixed bag of parts on this bike and that we are going to need to see more pictures and info about the bike to help properly. If you need to see a diagram from my service manual I can post one. It clearly list this hose as a air vent tube.

As for the carbs not being 93 I myself would have not put 93 carbs on a 96 or newer motor but that is just me.
If you have a diagram that indicates what the hoses are then definately post it.
Even if you'd bought a 919 motor without carbs you wouldn't bother running the 893 carbs you already have?
 

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If you have a diagram that indicates what the hoses are then definately post it.
Even if you'd bought a 919 motor without carbs you wouldn't bother running the 893 carbs you already have?
I just took a good look at the pic of his carbs and they are absolutely newer than 93 because they have the TPS on them. You can see it on the left handside of the carbs.
 

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It clearly states that it is a air vent tube. From the factory 96-99 919 motors use the carb sync hole in the number 3 cylinder intake runner to provide vacuum for the fuel tap. The hose that is at the top of the carbs is just an air vent for the carbs and attaches to nothing. It sits in a small bracker that is attached to the side of the frame. Since he stated that the hose wasn't hooked up to anything and had no place to hook up to I just assumed that both the motor and the carbs were 919. Plus if the motor starts and runs and will idle if he holds open the throttle by hand then obviously the fuel tap is getting vacuum or the carbs would not be getting fuel and the bike would not run at all.

Here is the pic.

http://i954.photobucket.com/albums/ae24/roland5color/airventtubes.jpg?t=1260282085
 

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I just took a good look at the pic of his carbs and they are absolutely newer than 93 because they have the TPS on them. You can see it on the left handside of the carbs.
According to the fiche the '93 also has the TPS, although I have heard US models don't have it?
 
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