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Main Area => General GS500 Discussion => Topic started by: seamax on November 02, 2010, 10:42:19 PM

Title: Stupid Mistake = Fuel Leak
Post by: seamax on November 02, 2010, 10:42:19 PM
I was low on gas commuting home tonight so I thought I set her to RES but instead she was on PRI. Anyways 5 hours later I started smelling gas in the garage. Went out to check and of course there is a very small puddle of gas under her. She had been on PRI since I got home. Switch the petcock back to ON.

Since it was late I did not check to see where it was leaking from but I bet from the filters.

I believe if your float is set correctly this is not suppose to happen but since my bike was on the sidestand could the carbs still leak due to the lean. The amount of gas leaked was very small and I still have gas in the tank. Should I worry about my floats? Don't really want to take anything apart until she gets winterized later in the season.
Title: Re: Stupid Mistake = Fuel Leak
Post by: JB848 on November 02, 2010, 11:01:55 PM
I did this same thing once before and I didn't have any issues after. But I think this is a Budhha question :thumb:
Title: Re: Stupid Mistake = Fuel Leak
Post by: skirecs on November 02, 2010, 11:42:06 PM
If you leave it on prime for a long time, and the floats aren't set perfectly or the needle valves didn't seat properly fuel can fill up the carbs, up the jets and back out to the airbox, and then out the airbox drain onto the ground

a cylinder might be a little flooded, so if you really care, take out the plugs, crank it for a second, put them back, and start it

it'll be fine, its happened to me before a couple times, i never took the time to de-flood
Title: Re: Stupid Mistake = Fuel Leak
Post by: Jared on November 03, 2010, 04:50:55 AM
Check your oil level/ crankcase for a heavy smell of fuel too....if the oil seems watery and stinks heavily of gas -change your oil....
If you're close to needing an oil change - might as well do it now... It doesn't always leak just into the airbox...

Just overnight- probably wont have this problem- but engines/rebuilds aren't always fun and cheap...
Title: Re: Stupid Mistake = Fuel Leak
Post by: seamax on November 03, 2010, 07:35:50 AM
Thanks for all the tips. So this morning there was no more leakage because there wasn't a puddle of gas on the floor like last night. I touched my air filter pods and they seem to be dry so I think the gas came from the overflow tube. Did not have time to check the oil or plugs because of my fairings. Anyways put her on full choke and she started up fine. She actually started a little different. Usually on full chocke she would rev up to about 4500 rpm right away but this morning on full choke she stayed at around 1500 for about 20-30 sec before jumping to 4500. Rode 10 miles to work without any issues so I think the floats are perfectly align but not off too much to be of a concern.
Title: Re: Stupid Mistake = Fuel Leak
Post by: skirecs on November 03, 2010, 09:56:51 AM
there was probably gas all up in there thats why the revs stayed low until it burned it all off
Title: Re: Stupid Mistake = Fuel Leak
Post by: The Buddha on November 03, 2010, 11:27:57 AM
Your floats would have to be high or some dirt holding em partially open ... however remmeber they are not supposed to be able to hold back a whole tank of gas. So dont be too hard on it, just U tube check it and set it right. Its happened to everyone ...
Cool.
Buddha.
Title: Re: Stupid Mistake = Fuel Leak
Post by: JB848 on November 03, 2010, 08:02:51 PM
So your saying the more gas you have in the tank the more the pressure on the floats when on prime? The reason why I ask is I normally store the 90 GSE with at least a half a tank with Sta-bil in it. I would think it would be good practice to leave it on pri in storage to keep fresh fuel in the system as it evaporates?
Title: Re: Stupid Mistake = Fuel Leak
Post by: bigfatcat on November 04, 2010, 06:21:13 AM
Whenever I forget to turn the fuel off I'll pull the plugs and crank it a bit to get any liquid fuel out of the cylinders - to prevent the condition known as 'hydrolock' which can theoretically damage the engine.
Title: Re: Stupid Mistake = Fuel Leak
Post by: The Buddha on November 04, 2010, 07:24:40 AM
Quote from: JB848 on November 03, 2010, 08:02:51 PM
So your saying the more gas you have in the tank the more the pressure on the floats when on prime? The reason why I ask is I normally store the 90 GSE with at least a half a tank with Sta-bil in it. I would think it would be good practice to leave it on pri in storage to keep fresh fuel in the system as it evaporates?

You genius ... I am telling you nearly the opposite ...
BTW I ahve seen gas gum up, stick the floats open, flow from teh tank drains into the airbox, gums up and literally the whole system had black tar on it ... nasty.
Cool.
Buddha.
Title: Re: Stupid Mistake = Fuel Leak
Post by: gsJack on November 04, 2010, 09:18:17 AM
It's a good practice not to leave it on prime but my old Hondas didn't have a prime position on the petcocks and you were supposed to turn it to off when parking the bike.  I never did and never had a problem leaving it at the on or res position all the time from 84 to 99 when I got my first GS, I put 230k miles on those 4 old Hondas.

On the other hand after I got the 02 GS I parked my 97 GS with over 80k miles on it never having had a gas leak problem.  I would still use it occasionally and always checked the oil first.  One day it was overfull a lot and smelled like gas and it had leaked gas into the crankcase while parked, I had left it in PRI for some reason.  I change the oil and used it and never left it in prime again.  If the float needle valve is just held open with a spec of dirt it will frequently purge itself and have no further problem.
Title: Re: Stupid Mistake = Fuel Leak
Post by: Suzuki Stevo on November 04, 2010, 05:54:02 PM
Quote from: The Buddha on November 03, 2010, 11:27:57 AMhowever remmeber they are not supposed to be able to hold back a whole tank of gas.
Sorry, but that is exactly what they are supposed to be able to hold back, what do you think the needles are doing while your riding? Their not dealing with a different amount of gas just because the engine is running?
Title: Re: Stupid Mistake = Fuel Leak
Post by: seamax on November 05, 2010, 07:51:21 AM
Quote from: Suzuki Stevo on November 04, 2010, 05:54:02 PM
Quote from: The Buddha on November 03, 2010, 11:27:57 AMhowever remmeber they are not supposed to be able to hold back a whole tank of gas.
Sorry, but that is exactly what they are supposed to be able to hold back, what do you think the needles are doing while your riding? Their not dealing with a different amount of gas just because the engine is running?

now I'm confuse again.

so if the floats are perfectly set are they suppose to or not hold back full tank of gas when the petcock is on prime? does it matter whether the back is leaning or not? and if the leak is very minimal on prime is this OK for an older bike?
Title: Re: Stupid Mistake = Fuel Leak
Post by: Suzuki Stevo on November 05, 2010, 08:42:07 AM
In a perfect world the gas comes in, the float goes up, the needle goes into the seat, the gas stops...in a perfect world, leaving your bike on Prime should not be an issue IF your needle, seat, and float are in fine working order.

I'v been wrenching (Pro/Non Pro) since the mid '60s and have a firm grasp on mechanical principal  :whisper:
Title: Re: Stupid Mistake = Fuel Leak
Post by: Suzuki Stevo on November 05, 2010, 08:44:21 AM
Quote from: seamax on November 05, 2010, 07:51:21 AM
Quote from: Suzuki Stevo on November 04, 2010, 05:54:02 PM
Quote from: The Buddha on November 03, 2010, 11:27:57 AMhowever remmeber they are not supposed to be able to hold back a whole tank of gas.
Sorry, but that is exactly what they are supposed to be able to hold back, what do you think the needles are doing while your riding? Their not dealing with a different amount of gas just because the engine is running?

now I'm confuse again.

so if the floats are perfectly set are they suppose to or not hold back full tank of gas when the petcock is on prime? does it matter whether the back is leaning or not? and if the leak is very minimal on prime is this OK for an older bike?
YES...Your needles should be able to hold back a full tank of gas if everything is in fine working order.
Title: Re: Stupid Mistake = Fuel Leak
Post by: reload on November 05, 2010, 08:52:26 AM
...so you're saying a valve should be able to stop the flow when closed and start the flow when open? no matter what fuel level? outrageous!! :icon_lol: :icon_lol: :icon_lol:
Title: Re: Stupid Mistake = Fuel Leak
Post by: The Buddha on November 05, 2010, 08:56:33 AM
OK stevo - they can in theory hold that tank of gas back, however when running they have a lot of other factors including the fact that they open regularly enough ... in fact they actually never fully close, they are usually on the verge of closing but stay open. The fact tha fun bags runnign keeps it from getting affected by a tiny speck of rust/dirt also. If the bike is oveflowing @ the floats you would never feel it if it was doing ti just a wee bit, it will get sucked in and burnt, or a bit will go to the air box and drain.

The floats can hold back the tank ... yes under ideal circumstances. However they can function just fine if they dont as well, and the problem could well be somewhere else - like dirt if they dont hold back the tank when its sitting in prime.

Yes it can lead to hydrolock if it overflows. But it usually would overflow into the airbox not the engine. Usually ... meaning parked on level ground on center/side stand.

Cool.
Buddha.
Title: Re: Stupid Mistake = Fuel Leak
Post by: gsJack on November 05, 2010, 09:42:18 AM
Like I said above the the Honda float needle valves will hold back a full tank of gas all night, all week, or all winter like they did for me for 15 years and 230k pre GS miles.  Maybe Honda makes better needle valves.  :oops:  I've been wrenching for 62 years since 1948 when I went to work in a garage at age 15 but am no longer sure I have as firm a grasp on anything as I once had.   :icon_lol:
Title: Re: Stupid Mistake = Fuel Leak
Post by: The Buddha on November 05, 2010, 09:54:48 AM
So will a GS is its been well maintained, however the culprit can be in teh tank or gas too if it does not, its not just its fault.
Honda uses keihein carbs mostly, I have found their needles and seats from the early 80's especially a good bit superior. Where they suck is the fitting between the carbs. Especially 1-2 and 3-4 if its a 4 cyl. They leak far too often for my liking. I've never seen that go on a mikuni rack.
Cool.
Buddha.
Title: Re: Stupid Mistake = Fuel Leak
Post by: Suzuki Stevo on November 05, 2010, 11:21:40 AM
Quote from: gsJack on November 05, 2010, 09:42:18 AMbut am no longer sure I have as firm a grasp on anything as I once had.   :icon_lol:
Ahhhhhh, you have an excuse now, my line is "here you read it, I can't focus on it"   ;)
Title: Re: Stupid Mistake = Fuel Leak
Post by: JB848 on November 05, 2010, 08:45:56 PM
Quote from: The Buddha on November 04, 2010, 07:24:40 AM
Quote from: JB848 on November 03, 2010, 08:02:51 PM
So your saying the more gas you have in the tank the more the pressure on the floats when on prime? The reason why I ask is I normally store the 90 GSE with at least a half a tank with Sta-bil in it. I would think it would be good practice to leave it on pri in storage to keep fresh fuel in the system as it evaporates?

You genius ... I am telling you nearly the opposite ...
BTW I have seen gas gum up, stick the floats open, flow from the tank drains into the airbox, gums up and literally the whole system had black tar on it ... nasty.
Cool.
Buddha.

Mr Buddha if I use Sta-Bil properly there is no way the gas can "GUM UP" it will not let the gas coagulate into a sludge. So what I was asking if there is more air would that not be a better way of doing things?
Title: Re: Stupid Mistake = Fuel Leak
Post by: skirecs on November 06, 2010, 03:15:19 PM
i just did this last night

bout a gallon in the parking lot

21 year old valves and seats are a bit leaky i guess
Title: Re: Stupid Mistake = Fuel Leak
Post by: Suzuki Stevo on November 06, 2010, 03:48:38 PM
Quote from: skirecs on November 06, 2010, 03:15:19 PM
i just did this last night

bout a gallon in the parking lot

21 year old valves and seats are a bit leaky i guess
But probably work fine while riding or left in the On position?
Title: Re: Stupid Mistake = Fuel Leak
Post by: skirecs on November 06, 2010, 06:06:29 PM
yeah i rode around on prime for months before fixing my vacuum line, turned it to ON when parked

now its fixed so ON all the time