Leaking gallons of Gas with bike turned off IDEAS?

I noticed the bike leaking the other day and put a gallon of gas in an empty tank. Two days later, i checked on the bike and the tank was bone dry. The wooden floor of my shed had absorbed the full gallon.
So I pulled the tank off and took apart the petcock not really knowing where to start looking. The seals / gaskets in the petcock seem to be just fine. It even had a little gas still in it. so i put it back together and put the tank back on the bike. Surching further I noticed that the gas had left a streak where it had been leaking on the plastic behind the carbs where the boots meet the plastic. The streaks are only on the first two carbs if you're counting from the left side sitting on the bike.
So i was thinking maybe its a stuck needle valve? and the gas is just coming out the first place it can...

but before i start it up with carb cleaner running through it, is there anything else i should check? i figured if the cleaner didn’t unstick things, then i would have to pull the carbs and soak them... which i really don’t want to mess with cause i have a feeling that if i take them out and pull them apart I’ll never get it running again I am the furthest thing from a mechanic hahaha

 

Was your petcock on prime, on, or reserve? If on prime, then you are essentially leaving the petcock open.

Will the bike run? If so, then you may not have a badly leaking or stuck float, it may be minor. Carb cleaner will not help if the needle valve is bad, but it would help *maybe* if the float is getting stuck.

If it is leaking from the carbs, you have the right idea! I would suggest you start it up and shut it down, and tell us what you see. Can you get to the air filter to see if gas is getting in there? If so, then it may be draining down into your oil too! That is a bad thing.

 

My petcock was on prime! Do you think that in itself was the problem?

What should I leave the petcock on when the bike is off?

(I usually start it in prime, then switch it to run, so most of the time I end up leaving in run/on when I turn the bike off)

I will work on it tomorrow evening after work and try to get into the air filter before starting it up. I hope this isn’t the case, but it sounds like it could be :-( if it has gotten in the air filter then I suppose I should go ahead and change out the oil and clean the carbs before starting it again???

 

If your petcock is on prime, the gas is running! Always leave it in run or reserve when your bike is off.

 

Jazzmoose is right. These petcocks are meant to be left in on. (Run.) I only use prime to fill up my carbs after draining them. My best guess is that you have an open or stuck float in one or more of your carbs, and the gas is draining into the intake and the engine. It probably would get in your oil.

Have you ever had liquid gas come out the tailpipe?

You probably need to start up the bike and tap the bottom of the carb bowls to get the float to release. If that doesn't work, then a rebuild is in order!

 

stuck float, she seems to have i'd say. Even if the petcock is left in prime no gas should leak. However thats a perfect world scenario, in the real world floatvalves get stuck, and then piss all your gas out if it is left in prime.

Most people find a solid tap with a hammer ggets it unstuck

good luck!

 

Aschulhoff:

"Prime" is only to refill the carbs after you've drained them or run out of gas. Even then you should switch it to "Run" after the engine starts.

If your petcock is working properly you should be able to leave it on "Run" at all other times with no fuel leakage.

Good luck-
Herb

 

ok thank you for your help thus far guys...

I took out the air filter... it reeks of gas...
I opened the top of the crank case.. and gave it a sniff... it also reeks of gas!

so I was thinking:
should i pull the fule line off the petcock and poor just enough gas in the tank to have it start coming out then put the hose back on and add a little carb cleaner and like a cup of gas to the tank... throw the petcock in prime to let the gas and carb cleaner into the carbs... (keeping the air filter off so if gas starts to come out i can sop it up with something) then let it sit in the carbs for a little while / tap on the bottom of them with like the back of a screwdriver trying to dislodge anything... then after that... add a little more gas and wait to see if it comes out into the air box again... and if it does then pull the carbs and rebuild them and if it doesn’t, do you think its all good? after i do that, i'll drain the oil and put fresh oil in...

About the oil...
Where is the bolt to drain the oil?
What kind of oil should i use in the bike?
How many quarts to i use to fill it back up?
And is there anything else i should do to clean out the crank case since gas has gotten in it, other than just changing the oil??

You all are wonderful I firmly believe that registering on this site was the best upgrade for my XJ physically

 

Thanks for the praise, nice to hear. I cannot comment on the oil plug but the oil change is definitely in order. As for your carbs, I will HIGHLY recommend you pull them and clean them rather than try to get by with just trying to flush them. Waste of time in my opinion. If your going to spend the time, pulling them is hands down the best way to address your issue. This way you get your eyes on the internals and can judge what is in order and what isn't. Let's put yourself in my shoes. I once had an old Honda 350 that ran poorly. Turns out the previous owner had simply used fiberglass re-enforced tape to repair a torn CV diaphragm and the fuel had jellied the adhesive leaving behind all the goo and fibers which blocked up a bunch of stuff. No amount of flushing would have fixed the issue. I hope you see the point.

 

mmm rob you make a strong point lol... i just don’t have the know how to do it myself, maybe when my CD arrives i'll give it a go... but i probably still wont have the money for it.

if i take them apart i have to get a rebuild kit for each carb right?

haha i work as a white water raft guide and make about 30$ per trip but i don’t get trips every day... I hope my trip tomorrow brings me a nice tip! it would go right into my carbs...

I just got:
5$ - a bottle of sea foam
7$ - two qts of Valvoline motorcycle 4 stroke 10w-40 oil cause they didn’t have 20w-40 on hand... but i don’t think it will be a problem in my bike, unless someone on here knows something about it i don’t lol...
4$ - oil filter, i figure i might as well change it out as well if gas stops leaking into the crank case.

 

oil and filter change should take 2.6 quarts of oil on your 550.
SAE 20W40 is recommended for temperatures above 40 degrees F

I would suggest the removal of carbs for thorough cleaning and inspection.

Sounds like your petcock could be leaking, take it apart and check for worn parts, broken diaphragm or spring.

 

Not necesarily, I pulled mine apart, cleaned them and reassembled them with all of the same parts. Except for the bowl gasket, which I cut new ones from gasket material I had here at the house. All of the parts in mine were good as new once they were cleaned of the gunk.

As of matter of fact a Yamaha mechanic told me that most of the carb kits he sells are for people that insist that they have new parts in the carb. He claims that most of the time these kits are a waste of money.

I haven't had any problems with my carbs after a Very thorough cleaning.

 

With DC on this one Aschulhoff, you needn't get rebuild kits for a cleaning. Only if you find damaged parts should you source new kits. Just use care in disassembly and you should be alright. I also recommend you disassemble the carbs one at a time, this way you don't mix parts and, God forbid, you arent' sure how it all goes back together, you have an unsullied example right next to it! Good luck, I expect you'll be alright once you finish cleaning. Have a great Memorial Day weekend and take a moment to remember why we celebrate this day.

 

awesome robert, thats good news for sure...

I'm planning on takeing them off the bike and working on it tomorrow.. but i dont plan on getting to far into them untill i get the XJ CD or manule in the mail. I'll be sure to post on here as things go... i'll probably need help hahaha...

does any one know of a good place to get just the gaskets or maybe some gasket material i can cut new ones out of... cause if no one has been in these carbs for like 24 year lol i'm afraid they might just crumple / fall apart on me.

 

Your local automotive parts store should have something for you.
I used (as the label states) a rubber-fiber material, 1/32" thick, for sealing oil, coolant, gasoline.

 

Here is a decent link http://www.mcmaster.com/ . They seem well stocked.

 

The update.... good and bad I suppose.

1. I ran carb cleaner threw the bike, and tapped the float bowl on carb number 1 and 2 which were the leaking carbs... this unstuck the floats in carb number 1 but not in carb number 2...

2. I pulled the carbs and opened just crab number two removed the float and found that the float needle while not warn down or blunt, did have a small crease in it.. i used my nail to massage the rubber around it till it took its normal shape.. there wasn’t really any grime or build up in the carb itself so i didn’t mess with it any further... i think the sea foam i used must have really done the trick on them... so i put it back together and installed it back on the bike...

3. I used black silicon to coat the carb boots since they had more cracks in them than i original saw with them on the bike... there nicely coated now! and not leaking any air

4. NO MORE GAS LEAK!!!!!

5. I drained the oil, which was thin as water from all the gas... pulled the old oil filter out which had some mettle files in it but not to bad... put in a new oil filter and put in 2.6 qts of 20-w40 motorcycle oil back in the bike...

6. I put a new battery in the bike.

7. I started the bike... with no problems but it roared up to 4000rpms and wouldn’t come back down... so i turned it off... then started it again with no choke on and it started fine but roared right back up to 4000rpms and just didn’t sound as smooth as it used to. I asked my neighbor for help with it and he adjusted the idle screw on the carb, saying that it probably moved when i took the carbs apart... after that, it wouldn’t start quite as easy and when it would it wouldn’t run well at all and die out really easy...
Even with the choke all the way on it wouldn’t get over 2000rpms before dieing out... and died out if I turned the throttle a little so there was more tinkering with the idle screw after which it wouldn’t start at all. :-(
Pulled the spark plugs just to see if it was flooded but they weren’t wet but a little black with carbon... polished them off a little and tested them for spark…(good solid spark on all 4) so I put them back but still no starting luck...

any ides?

 

Your throttle cable incorrectly installed, choke cable not seated in its holder, could be your diaphragm needle being stuck. This is by no means a full list, just a few off the top of my head. Good luck tracking it down, sounds like your making great progress.

 

That sounds exactly like the symptoms of my bike when it was not synchronized. Search the forum for how to do this, there are several ways. I find that while I am synchronizing my carbs, the idle will go from 4,000 down to 1,000 just from a few slight turns of the screws in between the carbs.

 

I checked the throttle cable it seems to be installed correctly and the choke cable is seated in its holder...

I didn't think I would need to sync the carbs cause i didn't mess with anything aside from taking the connection plate off the bottom and opened the float bowl on carb number two but we didn’t go into the vacuum camber at all on any of them... so I thought maybe the only things that changed would be the idle adjustment screw on the bottom bar that holds the 4 carbs together...