Gas Leaking Everywhere!

[Anonymous]

Yesterday I was out riding my 1980 GS850GT and everything was fine except for one stop where it was sitting in the sun. I had a difficult time starting it up - the gas tank was releasing pressure as I walked up to it, so I thought it was some kind of vapor lock. Well, I got it started and finished the day.

Then last night I was smelling gas, and just thought that it must be the fumes releasing from the tank again.

So...this morning the gas smell was really strong and I went out to check and their was a large (5 x 12 inches) puddle of what seemed to be gas underneath my bike. It seems to be dripping out of the air filter cover and out of a tube that comes out of the bottom of the filter housing and dangles loose.

Can anyone tell me why this would happen? And Is the tube supposed to be there - it looks like a drain tube of some kind unless it's disconnected from something.

I haven't popped open the air filter housing yet - I'll do that tonight. But I wanted to get some knowledge before I tore into it so I would know what I was doing.

--Dwight

[lhanscom]

Usually that's a stuck float, or an O-ring on the float valve gone bad. It also sounds like your petcock isn't shutting off. Before running her again, check your oil, if your carbs are overflowing, you may have gas mixed with your oil, not good for things. If your oil level has increased, change your oil before running it.

[Anonymous]

The rubber tubes that gas is coming out of under your bike are overflow tubes that come from your carbs. There are two of them. Put the petcock in the "on" position and disconnect the gas line from your gas tank. If your petcock is good there wont be any gas coming out of the tank because the thing is turned on my a vacuum, produced from your number 2 carb. So when the bike is on the gas flows and when it?s off the petcock is off. The reason to check your oil is the gas overflows into your cylinders and seeps into your oil. (I don?t know why it doesn?t just run out the overflow)And about the sun... maybe when the tank became pressurized from the heat of the sun it some how damaged your petcock so now it doesn?t turn off. Hope this helps.

[frosty5011]

I think Luke has hit the nail on the head.

By the tube leaking fuel......I think Dwight meant the drainage tube on the the bottom of the 850 airbox.......not the overflow/vent tubes from the carbs.

And Dwight........as Beckius and Luke have stated, make sure you didn't get any gas contamination in your oil/crankcase.

[Anonymous]

You're right. I was seeing it come out of the tube from the bottom of the airfilter box. So somehow gas was getting that far.

I am home now and have the tank off and the filter covers off and have removed the air filter. I'm not sure how to tell from here where the gas was coming from.

If I'm looking in at the openings from the carbs I see the closest one to the left side of the bike more gunky than the others so I wonder if it isn't coming out of that carb??? It guess that could also just be because the bike leans to the left when on it's stand, so if the fuel was built up enough in there it would make sense that that was the gunky spot.

So how do I know what to do next. Is there a way to isolate the problem or do I need to disassemble the carbs to get to the valves?

Thanks so much for your help!!!!

--Dwight

[Anonymous]

I just went out and checked the petcock like Luke suggested and I think that at least some of my problems might be there. I have a manual shut-off that was installed into the line downline from the petcock. I've used that some and when I took the tank off - that was closed. I opened up the manual valve and sure enough - gas kept pouring out. So...I'm assuming that means the petcock is shot right?

What about the valves - do I need to check those and how far do I need to dig into the carbs in order to check those?

--Dwight

[arveejay]

Hi Dwigbrad, To get to the float valves just remove the pin which holds the floats in place. Be careful when removing these pins as if they are a tight fit and are removed improperly you might break a float tang, this is the part which the pin sits in to allow the float to pivot. If you mix the floats up they might need set again. I think there is a phillips screw which holds the valve in place. Remove the screw and the little clip and the float valves will just pull right out.

[Anonymous]

my two pennys worth.

if you have a leaky fuel tap you will find that it drips everso slightly and even more so if you switch from main to reserve. When it does this, the petrol drips onto the top of the airbox (directly below the tap) and may either run around it and onto the engine OR it will run past the airbox cover and into the airbox itself where it finds it's way to and through the little vent pipe at the bottom of the airbox.

Mostly you never notice the fuel loss as it happens when riding and you only change to reserver when you are going along.

This also happens if you take the tank off and don't keep the fuel pipe up and a little runs out onto the top of the airbox and goes the same way.

Get a new seal kit for the tap and if you have a tap like mine then take a look at the spring in the back as that makes a big difference !

madoc