GS "blew," oil everywhere

[Kijona]

Is there gas actually in the oil??  Does the oil on the dipstick smell like gas?  Maybe I'm missing something but i don't see how a stuck/leaking float would cause an oil leak...

-Jessie

Gas in the oil increasing the volume of liquid inside the crank, thus increasing the oil pressure until something finally gives.

FYI it's normal for some gas to be inside the crank but not excessive amounts.

[Watevaman]

 Yeah, that's what my uncle told me. The oil being thinner and less viscous means more liquid, increasing the pressure.

Thanks for the list of possible culprits. I have a Haynes manual but I'll probably end up at least taking the carb apart with my uncle, as nobody I know personally has any experience with carbs and I definitely don't want to screw it up.

Would the float needle also explain why I had gas seemingly dripping off of the air filter for about a week or two before this incident? I had read into it but didn't find anything other than that can be normal at times.

[BaltimoreGS]

But wouldn't a stuck float just let gas leak out the over flow?  And even then, only until the gas flows out of the lines if the engine is off and the petcock is working properly.  What am I missing?

-Jessie

[Kijona]

But wouldn't a stuck float just let gas leak out the over flow?  And even then, only until the gas flows out of the lines if the engine is off and the petcock is working properly.  What am I missing?

-Jessie

What's happening is there's gas coming up through the main jet and into the throat of the carburetor and then being sucked into the intake causing the fouled plugs. If there's a lot of gas it's probably seeping into the cylinder while it's not running. On the carburetor there's really no "overflow" to speak of. There's a vent line which is at the top of the carbs (which is above the intake), a vacuum line on the side of the carb, and the main fuel line that runs in around the bowls. There's really nowhere for the extra gas to go except inside the airbox or into the intake.

[Kijona]

I should say that I'm speaking on experience with the older style carbs. I'm not sure about the newer ones but my guess is they're pretty similar. I won't know for sure until I eventually pull the carbs on my 07.

Edit: Just looked at the video and he has an older bike, in which case the above applies.

[Kijona]

Yeah, that's what my uncle told me. The oil being thinner and less viscous means more liquid, increasing the pressure.

Thanks for the list of possible culprits. I have a Haynes manual but I'll probably end up at least taking the carb apart with my uncle, as nobody I know personally has any experience with carbs and I definitely don't want to screw it up.

Would the float needle also explain why I had gas seemingly dripping off of the air filter for about a week or two before this incident? I had read into it but didn't find anything other than that can be normal at times.

Dripping off...where? The bottom? Or actually inside the box? Is the drain line on the airbox connected properly? If there's gas inside the airbox (and a good amount), then yes...the floats would cause that.

Also...no offense but NOT GOOD if you have gas dripping from anywhere. For one it's a fire hazard...secondly it's a sign of a serious issue. Gas/water/oil dripping out of the run-off line coming from the bottom of the airbox is acceptable but shouldn't be a frequent sighting.

[BaltimoreGS]

But wouldn't a stuck float just let gas leak out the over flow?  And even then, only until the gas flows out of the lines if the engine is off and the petcock is working properly.  What am I missing?

-Jessie

What's happening is there's gas coming up through the main jet and into the throat of the carburetor and then being sucked into the intake causing the fouled plugs. If there's a lot of gas it's probably seeping into the cylinder while it's not running. On the carburetor there's really no "overflow" to speak of. There's a vent line which is at the top of the carbs (which is above the intake), a vacuum line on the side of the carb, and the main fuel line that runs in around the bowls. There's really nowhere for the extra gas to go except inside the airbox or into the intake.

I must have been thinking of my Yamaha's carb with the over flow.  But back to my original point, if the engine is off and the frame petcock is working properly the most fuel fuel you should have flow through a stuck float is just what is in the fuel line between the petcock and carb which can't be much.  And if the engine is running it should push excess fuel out the exhaust (even with a dead miss).  I'm just not seeing how his oil has become contaminated with gas to the point of causing a leak.  I think they are 2 separate problems.  My 2 cents...

-Jessie

[Watevaman]

Yeah, that's what my uncle told me. The oil being thinner and less viscous means more liquid, increasing the pressure.

Thanks for the list of possible culprits. I have a Haynes manual but I'll probably end up at least taking the carb apart with my uncle, as nobody I know personally has any experience with carbs and I definitely don't want to screw it up.

Would the float needle also explain why I had gas seemingly dripping off of the air filter for about a week or two before this incident? I had read into it but didn't find anything other than that can be normal at times.

Dripping off...where? The bottom? Or actually inside the box? Is the drain line on the airbox connected properly? If there's gas inside the airbox (and a good amount), then yes...the floats would cause that.

Also...no offense but NOT GOOD if you have gas dripping from anywhere. For one it's a fire hazard...secondly it's a sign of a serious issue. Gas/water/oil dripping out of the run-off line coming from the bottom of the airbox is acceptable but shouldn't be a frequent sighting.

I don't have an airbox. It was dripping off the back plastic (as the air filter is slightly angled down towards the back) of the K&N lunchbox.

And yeah, I only rode one time in between noticing the gas leaking, and that was after about 5 days of not seeing anything. Whatever I found at the time in my searches obviously reinforced my thoughts of riding or otherwise I wouldn't have ridden the one time I did.

[Kijona]

But wouldn't a stuck float just let gas leak out the over flow?  And even then, only until the gas flows out of the lines if the engine is off and the petcock is working properly.  What am I missing?

-Jessie

What's happening is there's gas coming up through the main jet and into the throat of the carburetor and then being sucked into the intake causing the fouled plugs. If there's a lot of gas it's probably seeping into the cylinder while it's not running. On the carburetor there's really no "overflow" to speak of. There's a vent line which is at the top of the carbs (which is above the intake), a vacuum line on the side of the carb, and the main fuel line that runs in around the bowls. There's really nowhere for the extra gas to go except inside the airbox or into the intake.

I must have been thinking of my Yamaha's carb with the over flow.  But back to my original point, if the engine is off and the frame petcock is working properly the most fuel fuel you should have flow through a stuck float is just what is in the fuel line between the petcock and carb which can't be much.  And if the engine is running it should push excess fuel out the exhaust (even with a dead miss).  I'm just not seeing how his oil has become contaminated with gas to the point of causing a leak.  I think they are 2 separate problems.  My 2 cents...

-Jessie

Yes...you're right. Once would be almost inconsequential. However, multiply that by how many dozens of times he rode it before he realized there was gas getting into the crankcase. There is only one way for the gas to get into the crank and that's through the carb. I suppose it's possible this whole time his bike has only been running on one cylinder but that seems HIGHLY unlikely...unless he just didn't notice it...which I would also think would be highly unlikely.

[Kijona]

Yeah, that's what my uncle told me. The oil being thinner and less viscous means more liquid, increasing the pressure.

Thanks for the list of possible culprits. I have a Haynes manual but I'll probably end up at least taking the carb apart with my uncle, as nobody I know personally has any experience with carbs and I definitely don't want to screw it up.

Would the float needle also explain why I had gas seemingly dripping off of the air filter for about a week or two before this incident? I had read into it but didn't find anything other than that can be normal at times.

Dripping off...where? The bottom? Or actually inside the box? Is the drain line on the airbox connected properly? If there's gas inside the airbox (and a good amount), then yes...the floats would cause that.

Also...no offense but NOT GOOD if you have gas dripping from anywhere. For one it's a fire hazard...secondly it's a sign of a serious issue. Gas/water/oil dripping out of the run-off line coming from the bottom of the airbox is acceptable but shouldn't be a frequent sighting.

I don't have an airbox. It was dripping off the back plastic (as the air filter is slightly angled down towards the back) of the K&N lunchbox.

And yeah, I only rode one time in between noticing the gas leaking, and that was after about 5 days of not seeing anything. Whatever I found at the time in my searches obviously reinforced my thoughts of riding or otherwise I wouldn't have ridden the one time I did.

Sorry, I didn't mean to sound like I was criticizing you. I was just trying to give you the correct information. It's totally understandable that you heard it was okay and didn't worry about it - no harm done.

[Watevaman]

 Bit of a bump but I checked the floats just now and they're clean as a whistle and to my untrained eye they looked level when fully pushed in. I don't have calipers so I don't know if I can accurately measure as per the wiki.

Also, once I get my headers off (for those that have read the other thread, bolt sheared) I'm going to change the oil and see where this leak is coming from.


So as a question here (don't really want to clutter with another thread, but will do if you guys suggest it), what else could cause gas to get in the oil as much as it did? Any other parts of the carbs that would let gas past?

[BaltimoreGS]

Incorrectly routed fuel line or really worn out piston rings are the only options popping into my mind.

-Jessie

[Watevaman]

 Yeah, that other thread with the hosing diagram made me think about maybe fuel hoses being routed incorrectly but am I wrong in thinking that the bike running fine for the month before this event happening would rule that out? And the bike was sitting in the PO's garage without being run for who knows how long.

[BaltimoreGS]

There is only one fuel line to the carb so if you were riding it that rules out that possibility.  You could do a compression check to see how the rings are.  Was the oil really thin feeling?

-Jessie

[Watevaman]

 I didn't get a chance to feel the oil or anything at the time.

I believe my dad has a compression tester so I can probably do a test per your video.

[Paulcet]

So as a question here (don't really want to clutter with another thread, but will do if you guys suggest it), what else could cause gas to get in the oil as much as it did? Any other parts of the carbs that would let gas past?

Torn frame petcock diaphram

[BaltimoreGS]

I didn't get a chance to feel the oil or anything at the time.

I'm just still having trouble believing you got so much gas in your fuel that it got over filled to the point of blowing out a gasket.  My 2 cents...

-Jessie

[Watevaman]

I didn't get a chance to feel the oil or anything at the time.

I'm just still having trouble believing you got so much gas in your fuel that it got over filled to the point of blowing out a gasket.  My 2 cents...

-Jessie

Well I just went out and smelled the oil that's still sitting in there and it still reeks of gas so unless it's supposed to smell like that I don't know what else to say. Combined with the fouled right plug I don't know what else to tell you, which is why I'm wanting to check everything possible to ensure this doesn't happen again.

[bombsquad83]

So as a question here (don't really want to clutter with another thread, but will do if you guys suggest it), what else could cause gas to get in the oil as much as it did? Any other parts of the carbs that would let gas past?

Torn frame petcock diaphram

Did you check this?

[Watevaman]

 Nope, but I'll get to it either tomorrow afternoon or Thursday.

Although can someone explain what exactly happens if there's a torn diaphragm? I'm under the impression that the fuel would still flow into the carb bowls and sit there first, but obviously that's not the case if that can cause gas to get in the oil.