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Lesley
Guest
So I pulled the pilot key from the 93 carb it’s a 42, the main is a 165 and the emulsion tube has 5 holes on one side and 2 on the other. The emulsion tube in the twin cam carb has 1 hole on each side.
Frenchie
Member
My humble opinion would be get rid of the runners kit that is in carburetor. That would call for removing the adjustable needle, the main jet & emulsion tube. And the intermediate jet. You will not need this kit. Get it to a stock configuration write down the jet sizes you installed so you have a record. As stated by another member people just think more fuel flow is the answer, but it is not, getting the float level set properly and setting the idle screw will get you going out the gate.
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Lesley
Guest
The carb off of the 93 I have is stock. The emulsion tube has a bunch of holes and the diameter of the main jet is larger where you screw it in so the jets I have won’t fit. It is also 8 mm bolt instead of round. The 2002 emulsion tube has 2 holes and the jets I ordered fit. Now can I take the stock needle from the 93 and use it in the 2002 if I cue the needle jet too
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Lesley
Guest
the emulsion tube on top is the one from the 2002 with 1?hole on each side the one on the bottom is stock from the 1993 carb with 5 holes on one side and 4 on the other side
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Frenchie
Member
I do not see any photos. Check the emulsion tube length against the one you are taking out as you want to make sue it seats against the needle guide that sits below the tube tube when you screw it in. The needle guide is the silver colored parts you would see protruding into the bore area. The holes in the emulsion tube are there so air mixes with the fuel before it is sucked into the bore. You can use the stock needle as long as you are using stock numbered jets. The needle controls the amount of fuel that is allowed to pass through the jet as you are accelerating.
The top one is out of the 2002 it has a 180 jet and 2 holes, the bottom one is out of the stock 1993 Evo with 5 holes on one side and 3 on the other. I would use it with the stock needle but it has a 165 main jet. The one with 2 holes has a 180 jet . Also the jets are different diameter so not interchangeable.
dolt
Well-Known Member
Agree with Frenchie 100%. set the carb ub with all stock parts. I believe the lower needle jet holder (AKA emulstion tube) is the one the OP shoud be using. To be sure all parts are CV parts, find them at CV Performance.
https://cv-performance.com/
https://cv-performance.com/
Frenchie
Member
The lower emulsion tube and jet is the stock one. The upper photo is the tuners kit set up. I would go with the stock lower set up. At what speed where you getting the back fire through the carb? Though the upper set up said it had a 180 main jet do not be fooled that it is a bigger jet, as their number does not indicate a larger jet. The only way to tell with aftermarket jets is to use pin gauges to measure the jet bore size. When you replaced the fuel/air mixture did you replace the small o-ring that is in the carburetor bore?The fuel/air mixture screw configuration when you remove it is of course the fuel/air mixture screw, a spring, a flat washer that seats on the end of the spring coil and then a small o-ring. A lot of people bypass the small o-ring as they do not see it, but if you forget that o-ring you could be sucking air through the fuel air mixture screw as the o-ring could be damaged or not seating due to wear. The reason I ask when you are getting a back fire is to determine the circuit that is giving you issues. If you are at a red light and idling the fuel is metered through the fuel air mixture screw setting. As you are first moving from a red light the fuel is still passing through the idle mixture screw but fuel is also passing through the pilot jet. As you continue to accelerate from the light then the fuel is only passing through the pilot jet. When you are cruising from around 45 mile an hour and above the the fuel is only passing through the main jet circuit and the reverse happens when you are reducing speed. To set the fuel air mixture screw correctly just bottom the screw then back out two turns. Start the bike and back out screw and count turns in 1/4 turns until the idle stops rising, then turn in screw and count turns until bike wants to die. Then set screw to the middle position between the two. If your final setting is above 2 1/2 turns from screw being seated then you need to install a larger pilot jet and repeat the idle mixture screw adjustment. Again make sure you replaced the o-ring on the fuel air mixture screw it usually remains stuck in the carburetor body when you remove the screw, spring and flat washer, you will have to remove it with a small pick of some sort.
Frenchie
Member
These tuners kits are the modern day version of snake oil. If a person changes there exhaust from stock and puts a high flow air filter all they have to do is rest their fuel air mixture screw as it is set lean from the factory,increase their pilot jet size. These tuners kits have you install their emulsion tube with less holes in it so you are passing more fuel through the main circuit and less air to be mixed together.their jet sizes do not use the same sizing as stock jets. Here is another item for thought. These kits provide a drill bit and tell you to enlarge the vacuum hole on the slide and install their diaphragm spring which is either a lighter coil wound spring or a shorter spring. Then there are some kits that tell you to cut the stock spring to a certain length. They do this to reduce the vacuum requirement required to move the slide up thus pulling the needle out of its seat on the main jet quicker causing excessive fuel to be drawn through the main jet. Snake oil in a kit rather than a bottle.