carburetor leaks from bowl.

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rtaylor522

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hey all. quick question. got the bike together and it ran well today. Is it normal for fuel to come out of those two spiggots on the bottom of the bowl where the hoses are attached? Mine seems to leak a little out of both carbs when I let the bike sit on the driveway in the sun or anything like that. Could it just be the fuel expanding in the heat? it's not like they are gushing or anything but there is a very slow drip that will occur whenever there is fuel in the bowls and it undergoes temperature change. I double checked my float height and all seemed well there. When i shut off the petcocks and pull the drain plugs from the bowl it just drains out the normal amount of fuel and stops, so it's not as if the petcocks are leaking or the float is not shutting off the fuel. A little perplexed as I've never noticed this before and it makes quite an odor if I leave it in the garage.

Also noticed backfiring from the left carb/cylinder when cold. As soon as it heats up at idle (2-4 mins) it smooths out and runs like a champ....used to do this on the right cylinder on decel but I think I fixed that....but very smooth once it gets just a little heat on it....

Come to think of it how hard are those cam shaft seals to replace? My right side behind the ATU is leaking pretty well after this winter and it's running out of the atu side and down the right cylinder dripping on top of the bottom half of the engine. Thanks!

Happy Riding
 
OK good to know....so why do they have those pippers down there and how to I get fuel to stop coming out of them. This did'nt happen at all the other day when i ran it, and today it did'nt happen right away until the thing had been sitting in direct sunlight for 8 hours or so and it was at a very slow rate...Ideas?
 
Your float needle seats make be leaking very slightly, not enough to make it run bad but maybe enough so that after several hours, the fuel in the line drains into the bowls, overfilling them.
 
Now that sounds like a real good possibility...when I had the carbs apart the needle was starting to look sliiiiiightly grooved where it seats...I figured if it worked before it would work now but I bet thats not the case. Probably need to replace both of those then revisit this one.

About those cam seals...what is it that would casue the leaking behind the ATU cover? is there more than one seal to replace or just the one the cam shaft end rotates in?

Thanks!
 
By the way could that extra fuel seeping past be the cause of the backfire on the left side? Seems to me there was no backfire first start of the day (no fuel in bowls)...after sitting for hours and noticing the slight seepage when I started it thats when I had the backfire that sorted out after running for a bit.
 
The o rings that go around the float valve tubes might be dry rotted. I just replaced mine last night when i cleaned my carbs.
 
well I have a new turn of events...started to smell like gas in garage after i had already emptied float bowls. Opened up drains again and had about another half a bowls worth of gas in there (petcocks are off). So since if anything is done right I know those floats are (even both sides and set exactly at spec with gasket taken into acct.) and the petcocks don't leak when the hose is pulled off It must be those float needles not seating or the o-rings around the actual housing....i am so sick of pulling carbs I can not describe but thinking back I have this feeling that those o-rings are the originals (not replaced since I've had the bike) and with the grooves in the needles this must be the source of the problem....damn shame....BTW i'm parting with this bike so if anyone would like to make an offer (local or not) I'm game....would like to be in the 1500 range.

Bowie MD
 
Have the same issue here. I rebuilt the carb's a few weeks ago and then put them back on the bike. I started the bike up and it was running but a little rough as I haven't had the chance to synch everything. I went away on vacation and when I got back I noticed the smell of gas in the garage. The one carb seems to be leaking out of the bottom. When I pulled the drain plug the bowl was completely empty of fuel and the line to the carb was also empty. Am I looking for a crack or O'ring leak?
 
If I had to guess that sounds plausible...a leak from the needle seat, or the o ring...the b owl was empty because it all drained on top of your bike and garage floor and evaporated while you were gone. Good luck!
 
Wouldn't it be great if.....a question about leaking carbs couldn't be posted without describing the bikes, model, yr, carb ID and whether there are vacuum or manual fuel petcocks? Because without that info. one cannot either be helped or help much. Blue
 
Would'nt it be great if you were'nt so facetious......It's just a question man...I thought my sig had it in there anyways...I guess not....thanks for bringing it to my attention and making XS650.com a better place now that I'm educated.
Mine is a 1972 XS2, BS38, Manual Petcocks.


Thanks for everyone who has provided help without the tongue in cheek quippy comments.
 
My apologies. Blue

Please folks.....accompany your questions with indentification of the XS 650 model, year and relevant equipment information as practical
 
Last edited:
Most of the time 5twins and Grizld1 will not reply and they co-wrote the carb guide. Probably because all the answers to questions are in there, but people still fail to use the "tech" section, search function, or read the carb guide. I don't want to sound like an ass, and I am sorry if I do, (and this is directed to those who don't do it), but that guide saves a lot of time and thread/post space for Travis. "The thing is making this thing and that thing". I understand if someone did search and use all necessary tools and could not find the answer, but damn. This is not directed at you rtaylor, I'm just venting.
 
hotrdd said:
Have the same issue here. I rebuilt the carb's a few weeks ago and then put them back on the bike. I started the bike up and it was running but a little rough as I haven't had the chance to synch everything. I went away on vacation and when I got back I noticed the smell of gas in the garage. The one carb seems to be leaking out of the bottom. When I pulled the drain plug the bowl was completely empty of fuel and the line to the carb was also empty. Am I looking for a crack or O'ring leak?
Click to expand...
if bowl was empty look for a crack in the overflow tube, once the fuel level is below the top of the carb bowl it doesn't have any other way out unless the plug in the bottom of it leaks or a pin hole in bowl, a o-ring leak just by-passes the needle valve overflowing bowl it will empty your tank if shutoff is bad
 
bluebikerblan brought up a very valid point. These bikes were made over a 13 year period and there were many changes to mechanical and electrical items. When someone is asking for assistance, it is appropriate to give as much info as possible as to year.........is the engine the same year............is the wiring stock or modified etc. etc.
Unfortunately new members don't seem to realize this.

Its always better if someone uses the "Search" function, and then says they can't find the answer to their problems.

I suspect that many don't even know the "Tech" section has a wealth of information.
 
RG, that's kinda what I was meaning. I think that's why some members sound "testy". They are not being mean, just making a point. I've never met a mind reader.
 
I understand the usefulness of having that information, and at this point I'm not sure how to get my signature to work because I have it written in there and i see when looking back that it is not posting.

Just so you know my background I have a printed copy of that carb guide and it does'nt really specify about my specific situation (that I can find, it is rather large) and it is what I used for disassembly/rebuild of the carbs and tuning.

I actually believe this to be symptomatic of the needle valves/ o-rings when looking at all the possible solutions because if I shut off the fuel at the petcocks (that are'nt leaking) and empty the bowls, that should be it but 2 hours later, fuel is dripping again. I open up the bowl and there is a ton more gas that comes out. After that, problem solved no more dripping until I turn on the fuel system again. I know for sure it's not a leaking petcock combined with something else because I pulled the fuel hoses off of the shutoff valves.

I've been a member at 650garage since 2004 and additionally at 650rider and here. As you can see I rarely post but have been reading and "search" functioning the hell out of this place for quite sometime.

Thanks for the help, hope to get this resolved or atleast have an answer for the next owner.
 

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