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Lesley

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I would post this in the carb section but the posts are old. I have a new to me FXST It has a low opening throttle backfire through carb. Lean condition. My 93 had the same. I removed the carb, it’s dirty but I was going to replace the 45 pilot jet with a 46 and put 2 number 4 washers under the needle. The needle has a C clip? And there were 3 washers on top of the needle not under it. Out C clip is on the third from top groove. Any suggestions on needle setting? Thanks in advance.
 
Lesley said:
I would post this in the carb section but the posts are old. I have a new to me FXST It has a low opening throttle backfire through carb. Lean condition. My 93 had the same. I removed the carb, it’s dirty but I was going to replace the 45 pilot jet with a 46 and put 2 number 4 washers under the needle. The needle has a C clip? And there were 3 washers on top of the needle not under it. Out C clip is on the third from top groove. Any suggestions on needle setting? Thanks in advance.
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I still have the CV from the 93 I took off in 94 to put a SU on. I put it in a baggie with the manifold and sprayed it with WD40, it looks new. There is one more vacuum nipple on it and the bowl has a drain hose. If I plugged the extra vacuum and swapped needle and jets could I use that carb instead?
 
I can't think of a reason not to try the other carb. I have had low opening backfire (more spit) due to a misaligned accel. pump nozzle, stroke or crap under the accel pump wafer. Intake gasket leaks also cause this problem.
 
I just don’t know what the extra fuel inlet is for. It’s on same side as the main one but back towards manifold.
 
Very common for everyone to just keep adding fuel to a lean condition. Make absolutely sure there's no intake leak first. I use a propane bottle with a length of hose so it's easier to get in there. Also inspect the rubber diaphragm on the slide for pinholes.
 
The main jet does not have a number on it, just one dot
 
On the early cv carburetors you had an overboard drain attached to the float housing. On the newer carburetors the overboard drain was deleted for epa requirements. Then they installed an extra fitting which you are asking about, that fitting is used to run a hose to a charcoal canister for epa requirements. The vent hose from your fuel tank used to be open to the atmosphere but with the newer carburetor bikes it to also runs to the charcoal canister. The canister is located below the oil tank. It can be seen when you remove the rear tire, then remove the lower rear fender splash guard then remove the electronics caddy that holds the electrical components and it is in view. I stated that so you know where it is located. What you have with carburetor that has an adjustable main jet needle is a tuners kit that is why the main jet has a star on it and not a number on it. I would remove the tuners kit. Use the non adjustable needle and then use the jets that are numbered from the other carburetor. Make sure you set float level according to manual, it has to be at an angle when checking float level. And as stated above replace the intake manifold seals. There is only one fuel hose to carburetor an overboard fuel drain hose if it is an early carburetor and a vacuum hose that goes from the intake manifold to the voes switch. If Your fuel petcock is stock it will also have a vacuum hose that tees into the voes vacuum hose as the original petcock is vacuum operated. If you have an aftermarket Petcock it will not have a vacuum hose but make sure you turn off when you are not riding bike. Also check the carburetor diaphragm to make sure there are no tears in it and that it is seated properly under the black cover on top of carburetor.
 
Frenchie it is great that you share your knowledge with us.
Hopefully Lesley gets it dialed in.
 
Frenchie, thank you. I had forgotten about the charcoal canister as the 95 inch Evo I road from 99 till I gave it to my son didn’t have it but the 93 FXSTC did. I will plug that fitting and go from there. One thing, will the emulsion tube be different if it has the tuners jet in it. I have a rebuild kit on the way along with assorted jets. Is it ok to use the needle with the C clip? I reread your post, will get or remove from stock carb the needle and use it.
 
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