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Discussion Starter · #1 ·
I thought I had this figured out, but I guess not. When I shut the bike off (99 flstf) fuel starts to pour out of the hose coming out of the float bowl. So I take the bowl off, thinking that the float is sticking and it seemed fine, but there was a bit of debris at the bottom so I cleaned it out. Put it back together and everything seemed fine. BTW, sometimes the fuel would come out of the hose while waiting at an intersection with the bike running. So I come home from work and I ran out of fuel early, due to the loss of fuel from the hose, I switch to reserve just about 5 houses down from me. When I shut off the bike, fuel is coming out of the hose.

What is causing this, the dealer said it didnt do it for them when I had it TOWED to them about a month ago. Could switching to the reserve have anything to do with this? The bike only has about 15k miles, so the tank is pretty clean and I have a Rivera inline fuel filter. I am baffled, someone please help.
 

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cannibal......

Its either float level set too high, float damaged and partially sinking, or fuel inlet needle or seat damaged, failing to seal. Also, first thing, check out your fuel tank vent line and one way valve. Tank could be pressuring up, overpowering fuel needle in bowl, especially when engine is hot and bike is sitting off(happenned to me before, heats up fuel tank). Your filter rules out debris in needle, isn't a petcock problem either. If its not tank venting problem, I'd pull carb, remove bowl, remove float and pin, closely inspect needle and seat, replace if necessary. Also inspect float for any damage or cracks, tab which contacts needle. Reassemble float and needle, verify smooth up and down movement of float, set correct float level per manual.
 

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Discussion Starter · #3 ·
Thanks for the feedback,
I was hoping it would not be so involved. I guess I have to get the manual and just go for it. I am mechanically inclined, but carbs scare me, I have always worked on EFI cars.

BTW, does anyone know what the stock jetting is for a 99 flstf EVO? I only pulled out the main jet and it was a 170. I have an AC kit and drag pipes, doesnt that seem a little small? I am hearing alot of guys with 180/185/190 jets. The bike does not ping, the pipes are sooty, but WOT is a little weak. Any ideas?
 

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It ain't that difficult. Very first thing I'd check it fuel tank venting. If it's pressuring up, thats your problem. If it occurs again, immediately slowly and carefully loosen gas cap. If overflowing stops or you get a pressure release while loosening cap, its a tank vent problem. Be very carefull doing this with a full tank! If that doens't solve it, check float level setting and inlet needle and seat inspection.
 

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I had the same problem with my ride. The float would randomly stick and piss fuel out the overflow. I removed carb, cleaned everything and readjusted the float. Still occasionally leaked. I replaced the needle, inspected the seat and confirmed smooth float operation. Still occasionally leaked. Damn. I readjusted float to a very low setting (so much so it starved at WOT runs). Still occasionally leaked. DOH! I readjusted float to high setting. Still occasionally leaked. I'm one step away from taking the Mikuni plunge. I readjusted it back to a normal level and then it mysteriously quit leaking. Still baffles me to this day...
 

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Maj,

Good choice. i've owned a Mikuni 42mm, a S&S E carb which is on my Titan, and the Keihen stock carb with and without Thunderslide kit, and by far the best, smoothest performing carb was the Mikuni. The S&S are ok, but they have some negative traits. And the Mikuni doesn't have a butterfly and shaft upsetting, restricting airflow at WOT or any other position, it has a slide, on bearings at that in some models, and at WOT nothing but a needle in airflow. Japs have a better design, they just perform better.
 

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Discussion Starter · #7 ·
Problem solved, for now, but feels gutless

OK, upon disassembly, I found some crud on the fuel inlet needle stopper thing, cleaned it assembled, same problem. I started messing with the float height, and voila, problem solved. I have no manual on this, I kinda set it "barbarian style", but it seems to be working.

Now, this is what I found out, I have a 45 slow jet and a 170 main. The needle had 3 washers on it. (my plugs are always black). I took off 2 of the washers and reassembled. When trying to set the idle mixture, I can turn the screw 9 turns OUT without any Idle problem, but I can't close it down all the way. So, I'm guessing that the 45 slow jet is too BIG, am I on the right track?
AND, the bike is really gutless at WOT, is the 170 main too small?
This bike dynoed at only 58 rwhp and 70 ft/lbs of torque! This is with an air cleaner kit and pipes. I was told that this combo should be in the mid 60hp range. Could it be the tuning?

Someone please give me some help in tuning the carb, I just need a reference point.
Thanks in advance!
 

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Cannible,

On idle mixture screw, out is richer, in leaner. You shouldn't be able to run idle screw all the way closed without bike stalling so thats ok in that regard. Being able to adjust it out 9 full turns without affecting idle quality tells me the 45 is too small........the orifice in 45 will not allow you to adjust it too rich to cause idle to fall off in quality. Correct adjustment procedure is to start out about 2.5-3.5 turns out, start bike and ride till up to operating temp, then adjust idle mixture, first turning in screw til notable idle change, kinda a stumble, note position, then go out til same occurs or slight idle quality change, correct position is somewhere in the middle, leaning towards the leaner side I prefer. Somebody definitely richened up your midrange with 3 washers, too much, black plugs. More important is the thickness of these washers, if just common washers usually like .020-.030" in thickness, plus their inconsistant. Correct washers like from Dynojet are about .010-.015. Try a 175 or 180 main.
 

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Re: Problem solved, for now, but feels gutless

cannibal said:

Someone please give me some help in tuning the carb, I just need a reference point.
Thanks in advance!
Hmm, hey dude, taking into consideration your avatar, do you think that maybe your carb is possessed? :confused:
 

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Discussion Starter · #10 ·
Demonic possession of my carb would be the least of my spiritual worries! But that could be a possibility, anyone have a number for a good EXCORCIST?
 
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