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cheekybeast
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1,557 Posts
Discussion Starter · #1 ·
I ran out of gas on the freeway today. I called AAA and they brought me some gas. It did not start, so i had it towed to a friends house. While it is there, we get it to start by hooking it up to a trickle charger and cranking it a few times.

Now there is a MASSIVE gas leak on the left side of the bike, whenever the bike is running. When it is not running, there is no noticeable fuel leak. I removed the fairing and tried to find out where the leak is coming from, but I have not been able to see.

Does anyone know what the heck is going on?
 

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Habitual line-stepper
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11,594 Posts
What kind of bike is it? If it's fuel injected, you may have a leak on a seal AFTER the fuel pump. That's what it sounds like, and that would be why it doesnt run. Because the hose came off and no gas is getting to the engine..... could also be why you ran out of gas.
 

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cheekybeast
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1,557 Posts
Discussion Starter · #3 ·
its a 98 honda cbr 600 f3... which is carb'd

the thing is...

it did not leak before running out of gas...

and

the engine DOES run now.... it just squirts fuel out of the left side of the bike.
 

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Supmo
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717 Posts
I know little about bikes but pherhaps the tube that goes to the reserve port on the petcock popped off somehow....? Dunno if this would be the case but I know my tube popped off when I lifted the tank.......but I'm pretty sure it'd only leak if the petcock was set to reserve...dunno...just a thought.
 

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cheekybeast
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1,557 Posts
Discussion Starter · #5 ·
i only have 1 line going to my fuel petcock

and its still on, so its probably not that..

other than that i am so clueless as what is leaking right now.
 

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Habitual line-stepper
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11,594 Posts
It only leaks when it's on..... check the fuel line for cracks. The petcock on some bikes won't let gas through without a small vacuum, so it wont drain into the carbs when the bike is off. So when it's on it could be leaking through a crack in the fuel line.

It's probably on one of the ends, or near a bend. You said you couldnt see where it was coming from... which is wierd. It really sounds like it's a fuel line that cracked and MADE you run out of gas. Dry everything off real good, then run the bike very briefly and see where it's wet. Start a search for cracked things from there out.

Or wait till redstar gets online...
 

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cheekybeast
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1,557 Posts
Discussion Starter · #7 ·
the fairing has already been removed...

I havent been able to find where it is leaking yet... it is probably buried deep inside the bike.

I am wondering... what is the correlation between running out of gas and suddenly massively leaking fuel.
 

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Habitual line-stepper
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11,594 Posts
^ yeah, i saw you already took it off, so i edited my post.... like i said- i think the massive fuel leak CAUSED the running out of gas, not the other way around.

It would have to be BEFORE the carbs, or it wouldnt run well, and wouldnt be that big of a leak. The fuel line probably splits, to go to the right side carbs. So take off the right side fairing and check the fuel lines to the right side carbs.
 

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Habitual line-stepper
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11,594 Posts
I downloaded a service manual for your bike. The fuel splits off to the right 2 carbs via a plastic "T" fitting. This may have cracked. Or, the right side tube may have a small tear in it.

Good luck!
 

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Registered
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106 Posts
As suggested above, if your bike RUNS then FUEL, SPARK, and AIR are getting to your bike. If you actually SEE fuel spitting out of the side, there is a hole or more likely a crack where this gas is coming from. Does your bike run differently or sound different when ideling? What about RPM at idle.
 

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what? who? where?...
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595 Posts
kevinwilly said:
It only leaks when it's on..... check the fuel line for cracks....

+1 on this. Had this happen on my Motocross bike when I owned it. There was a crack in the line right by the pepcock. When it wasnt running you smelled gas, but, when it was running, gas would drip for the line...
 

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cheekybeast
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1,557 Posts
Discussion Starter · #13 ·
enos told me that it is probably a sticky float. he advised me to whack the bottem of the carb. i will try that tomorrow as i cannot see an odvious place where the fuel is leaking out of....any tips on that would be cool

also.... the bike does sound a lil different.... probably because its in a garage right now though. it sounds a lil more deep.
 

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Habitual line-stepper
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That's true, as you completely drain the fuel tank, the leftover sediment will be taken into the carbs. You can whack it to clear out the floats, but that crud is gonna be in there until you physically go and clean it out.

Usually that makes the bike just run bad, though- doesnt it? It sounded to me like gas was actually coming OUT of the fuel system... you may still have some bad floats, though.

A lot of people clean out the inside of their tanks once a year to prevent this. You'd be surprise how much crud gets in there.

BUT- if gas is spurting out of the system, this is not the problem. Check and see if it gets worse with throttle... i.e. under more pressure...
 

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Old school fool
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5,720 Posts
cheekybeast said:
enos told me that it is probably a sticky float. he advised me to whack the bottem of the carb. i will try that tomorrow as i cannot see an odvious place where the fuel is leaking out of....any tips on that would be cool

also.... the bike does sound a lil different.... probably because its in a garage right now though. it sounds a lil more deep.

And THAT, I believe is the right answer (after a fashion).

Here is what likely happened. You had some sediment (a little paint chip or a piece of sand would be enough) that was floating right there at the bottom of the tank. When you switched it over to the reserve and used every last drop, that piece of crap got sucked down into the carb and got lodged somewhere - I'm guessing in the needle valve.

That means that even though the float is working to close the fuel flow running into the carb, the needle valve is jammed open and allowing fuel to continue to rush in and overfill the bowl. The gasoline has all the pressure of the gas in the tank above it and is running out of the carb where it can, probably the overflow vent, which should be connected to a hose and dumping out the bottom of the bike. If your bike doesn't have that hose, someone may have removed it.

The reason it stops leaking fuel when you shut the bike off is that the petcock is vacuum controlled. It only opens when the engine is running. Without running the bike (and when it is nice and cold- no hot pipes to get gas on- and no smoking!) turn the petcock to the "Prime" position and your fuel will start to dump into the carbs. Follow the leaking fuel back to the carb that is the problem.

Beating on a carb isn't a good idea. They are senstive. It IS possible that whacking it might make the piece dislodge and fall into the bowl. This will solve your immediate problem. However, the piece will remain inside the carb until you go get it or the flow decides to send it somewhere else - at which point it might cause some other problem (like getting lodged in a jet). You are going to have to go get this thing.

Since you will know what carb it is in, take the rack off, pop the float bowl, turn it open side down and remove the float. (Cafeful not to bend anything and be careful not to strip out the screws - I've done that on at least one screw for every carb I've ever opened) The needle valve will be attached to the float and the crap should fall out of the valve and onto the bench (or it may be stuck on the valve or valve seat.) Spray out the bowl and the fuel passage with some carb cleaner just to make sure you have all the crap out.

If you haven't bent anything, everything should go back together easily. You may need a float bowl gasket but that should be it. Don't tweak anything, bend anything or do anything else while you are in there and the carb settings should be fine. The hardest part of this by far will be getting the rack off and on and the unhooking and rehooking the throtte cables. Otherwise it is not too tough.
 

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cheekybeast
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1,557 Posts
Discussion Starter · #16 · (Edited)
i just looked at the service manual.... dont know if i will be able to do that.

What is the rack? and how do i pop the float bowl off.

edit: i removed the gas tank, airbox/airfilter, and got to the things that look like throttle bodies. Around them are these golden tabs that are covering screws... its hard to describe. I dont know where to go from here.

Will i have to remove the entire carb to do this?
 

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Old school fool
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5,720 Posts
You're going to have to follow a manual just to make sure everything you do is right. If you lack mechanical aptitude, take the bike somewhere. Otherwise, all I can say is take your time and be gentle.

On every bike I've ever worked on, all four carbs are screwed onto a plate and come off as a whole unit. There are rubber boots between the carb and the cylinder head and there are usually clamps (that look like hose clamps) that hold the carbs inside the boots. Loosen the clamps and then work the whole rack off the rubber boots by gently wiggling it up and down. No prying!

Once you get them off, the float bowls should be easy to see. From the outside they look like what you see when you look at the bottom of a cerial bowl. Have some rags handy because when you lay them on the bench all the fuel remaining in the carbs is going to spill out all over. Only open the bowl of the one carb you know is having the problem and then do what I told you earlier.

Some carbs have metal tabs to prevent people from tampering with them or to act as a tell tale to let mechanics know you have violated the warranty. If your bike still has them, then that is a good sign that the bike has not been jetted or otherwise molested.
 

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cheekybeast
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1,557 Posts
Discussion Starter · #18 ·
Today me and my friend took apart the bike as much as we could. We followed the instructions exactly till the last instruction. Where it tells us to loosen the 4 clamps to remove the carb unit.

i could not get a screwdriver in there to remove most of the clamps. I could only undo the outer two cylinders. The inside two are rediculously cramped. We spent MANY hours trying to get to the inside two cylinders

We got so pissed. We put the whole thing back together. I really do not know what to do right now... I dont really want to spend the money to have the bike towed to the repair shop (they will probably charge like $100++), where they will charge me a LOT just to fix this.

Tomorrow we may try it again, when i feel better. But there was seriously no way to access those clamps on the inside cylinders. Also we couldnt freakin get the throttle position sensor plug off.

Are there... mechanics that come to your house? or maybe someone here on SBN can come look at it for me. I'd pay of course
 

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Old school fool
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5,720 Posts
If you've got a long screw driver and can get a couple of turns on the screw, you can loosen the clamp enough to turn push it around the boot and get it into a better position. Then loosen it the rest of the way.

You can always load the thing into a truck and take it to a shop, seems like it would be way cheaper to even rent a truck than it would be to have a mechanic make a house call.
 

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cheekybeast
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1,557 Posts
Discussion Starter · #20 ·
im taking another crack at it today. i feel much better. i was soooo angry/sad yesterday. If i dont get it this time ill think about taking it to a shop
 
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