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Discussion Starter · #1 ·
Troops,

'93 FXR/EVO. Long story made short is I had the tank off, relined it, installed a new petcock, new fuel line, new brass elbows. Pulled the carb off and pulled the bowel assembly off, cleaned and blew out everything. Needle looked good, then reassembled everything.

First short ride went well (so I thought). Next day while idling on the driveway (some slope, but not much), I noticed a good sized gas leak that I traced to the overflow line. Shut engine and petcock off and parked it. Note that if the petcock was open the leak persisted, as I'd expect.

Tonight I pulled the bottom of the carb off, and found no debris, the needle was still good, no debris on the seat (cleaned it anyway). I put in a new needle, checked the float level, and reassembled the carb.

Shortly after I opened the petcock I got a few drop drops of gas from the overflow line, then that stopped (plenty of fuel in the tank). In this process I noticed that the overflow line is ported not just into the bowel, but to the brass tube that runs up into the center of the carb. So 1) I'm trying to understand how that works, 2) why would it start and then stop dripping, and 3) does having the motor running affect this problem (is too late to start the bike, will do tomorrow).

Any ideas and/or theories are welcome and appreciated.
 

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Sounds float related to me.
Set to the wrong level or sticking or maybe punctured and not floating.
 

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Discussion Starter · #3 ·
Makes sense. When the float was out I tried to detect any gas in it, seemed OK. But it could be sticking when the bowel is put on. I'll check again and I might drop the float level a bit.

Still don't understand why the overflow appears to be ported to the brass tube which is way above the bowel's level and how it works if it is. Blowing on the overflow hose definitely pushes air through the tube.

Thanks Hillcat.
 

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I agree with hillcat. Since you had the bowl off and blew compressed air into the carb. Also you really can't adjust the float while the carb is on the bike. You're just guessing at it. The float when at it's proper height presses the rubber tipped needle against the fuel inlet. If that tip's compromised it will continue to allow fuel in.
 

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Discussion Starter · #5 · (Edited)
I agree with hillcat. Since you had the bowl off and blew compressed air into the carb. Also you really can't adjust the float while the carb is on the bike. You're just guessing at it. The float when at it's proper height presses the rubber tipped needle against the fuel inlet. If that tip's compromised it will continue to allow fuel in.
Agreed.

But I didn't blow compressed air into the carb since I noticed the leak. I only blew into the overflow line (by mouth while to bowel was off). When I used compressed air to clean the carb, it was off the bike.

I'll be taking the carb off to set the float.
 

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Oops guess I missed the part where you said you had it off. So much for that speed reading class! You should prolly stop saying you blew into the bowel too. LOL!
 

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Also, the float needle (from what little I understand) has been updated. Instead of triangle shaped, they are now square. Supposedly this is more reliable, from what a local mechanic told a buddy of mine. Agreed on the float, but might give the float needle a look while you are in there.

A photo of the plumbing you mention, maybe?
 

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Discussion Starter · #8 ·
Needle is new (triangular I think, didn't pay that much attention to it), seat is clean and smooth.
Will send pics, but won't be for a few days (ball games, BBQs, etc. coming up).
 

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Yeah they updated the design after it was determined it flopped around in the hole too much and sometimes got stuck.
 

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Troops,

'93 FXR/EVO. Long story made short is I had the tank off, relined it, installed a new petcock, new fuel line, new brass elbows. Pulled the carb off and pulled the bowel assembly off, cleaned and blew out everything. Needle looked good, then reassembled everything.

First short ride went well (so I thought). Next day while idling on the driveway (some slope, but not much), I noticed a good sized gas leak that I traced to the overflow line. Shut engine and petcock off and parked it. Note that if the petcock was open the leak persisted, as I'd expect.

Tonight I pulled the bottom of the carb off, and found no debris, the needle was still good, no debris on the seat (cleaned it anyway). I put in a new needle, checked the float level, and reassembled the carb.

Shortly after I opened the petcock I got a few drop drops of gas from the overflow line, then that stopped (plenty of fuel in the tank). In this process I noticed that the overflow line is ported not just into the bowel, but to the brass tube that runs up into the center of the carb. So 1) I'm trying to understand how that works, 2) why would it start and then stop dripping, and 3) does having the motor running affect this problem (is too late to start the bike, will do tomorrow).

Any ideas and/or theories are welcome and appreciated.
The syphon tube in the bowl may have a crack in it. It allows fuel to leak out even though the level is correct.
 

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Discussion Starter · #11 ·
Update

"JUST" pulled the carb.

The new needle is 4 sided (as was the one that was in there so I'm thinking someone as been inside before), and it's point is good.
Seat is nick free and clean. Unlike the automotive carbs I grew up it does not appear to be replaceable.
Float does not have gas in it, and it floats w/out sinking in a can of water.
Set the float level per spec, (11mm @ 17.5deg).
There is no binding, the float moves freely when assembled.
Would attach pic, but everything looks normal.

Re-assembled and on. Still leaks, when not running. BUT... only a slow drip. When I first noticed the leak it was leaking quite a bit. Since pulling the carb apart, etc. it leaks less.

The syphon tube (overflow pipe?) suggestion certainly makes a lot of sense. Is this not unusual? I'll pull the carb off and apart, and look at that. I may coat it w/epoxy (Devcon, JB, etc.) just to test idea.

Thanks all.
 

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Put the scooter on a jack so its level, see if it still leaks.

If that stops it, then you need to determine if the lean is correct. Short fork kick stand on a long fork scooter will cause this issue.

If the lean is good, lower the float a mil or two.
 
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