Whatever happened to that "disappearing fuel" thread? Was it Gen 1 or 2? Resolution?

[Semi-retired]

I swear (and my wife says, "Yes......too much")......that the gas gage on my 03 Midnight went down about a quarter tank a couple of weeks ago.....overnight in the garage.

 

The sighting window on the side cover is also now (I THINK), suspiciously reading HIGHER than when my oil was last changed.

 

IS it possible under any circumstances that fuel IS somehow draining into the crankcase on a Gen 2?

 

At the same time these visual clues are emerging, I also swear (sorry for so much profanity here!) that the engine is sounding considerably more "tickety, tickety" than usual.......which it WOULD BE, of course, if the crankcase oil had been recently diluted with a gallon or so of gasoline. (Or ANY amount, for that matter.)

 

Am I dreaming? Having a paranoia episode?

 

Is there any way to definitively check the oil for gasoline pollution?

 

I'm changing my oil today, even though it may not be "necessary", based on pure mileage interval. so, is there any way to test the "outgoing" old stuff for gasoline content (short of sending it to NASA for hydrocarbon analysis?) Like, put a small amount in a saucer and try to LIGHT it, for example?

 

Driving me nuts.

Thanks for any help/ideas/suggestions.

[XV1100SE]

Do you have the oem or aftermarket fuel pump? Do turn off the fuel petcock when you park for the night?

[videoarizona]

[XV1100SE]

Think this is the thread you were looking for - http://www.venturerider.org/forum/showthread.php?98739-Gasoline-vanishing&highlight=petcock

[Flyinfool]

First off, yes it is possible for gas to drain into the crankcase while parked. The way for that to happen is if you have an issue with one or more floats in the carbs. if the float vale is not sealing the gas can overflow, drain into the carb and from there drain into the cylinder, where is sneaks past the rings and into the oil.

 

If this is happening, starting the engine can be dangerous to the engine. IF it fires with one cylinder full of gas it will hydro lock and can damage the piston and/or connecting rod. So it is something to get right after to find if you have an issue.

 

As for testing the oil for gas. put a drop of oil on your finger. Smell it. You can smell the gas in the oil. Now rub that oil between your fingers compare it to a drop of new oil. If the drain oil feels thinner then it likely has gas in it. When you pour the oil from the drain pan into whatever container you put it into, pay attention to how much oil there is. If you have the same or more drain oil than what you put in, then you know something was added. Remember the filter will be full of oil. So you should always end up with less drain oil than the amount needed to fill to proper level.

[Semi-retired]

First off, ........if you have an issue with one or more floats in the carbs. if the float vale is not sealing the gas can overflow, drain into the carb and from there drain into the cylinder, where is sneaks past the rings and into the oil.

 

Would I have to be super unlucky to have the needle valve stuck open on the corresponding cylinder that just happened to stop with the valves open when I shut the key off?

 

As for testing the oil for gas. put a drop of oil on your finger. Smell it. You can smell the gas in the oil. Now rub that oil between your fingers compare it to a drop of new oil. If the drain oil feels thinner then it likely has gas in it. When you pour the oil from the drain pan into whatever container you put it into, pay attention to how much oil there is. If you have the same or more drain oil than what you put in, then you know something was added. Remember the filter will be full of oil. So you should always end up with less drain oil than the amount needed to fill to proper level.

I guess these two tests would be determine positively whether or not some gas got in there or not.

 

So many checks and balances.......so many measurements. It doesn't sound like you like my "put it in a saucer and LIGHT it" test!?!?! :-)

 

What's a tiny little "KABOOM!!!".....compared to gathering up all those graduated cylinders, beakers and measuring cups!!??

 

Too bad there isn't a way to dip a litmus strip into your oil and scan it with your cell phone......or, hey, I'd even pay the buck to mail it to Shell Oil and have them analyze it for me.

[Semi-retired]

Do you have the oem or aftermarket fuel pump? Do turn off the fuel petcock when you park for the night?

 

What's the scoop on the fuel pump, Don? (I missed the email!)

 

I DON'T turn off my fuel tap.........but, I guess I WILL from now on!

[XV1100SE]

The OEM pump has a shut off (flow preventer) when turned off. Not all after market pumps do this and fuel can trickle into the carbs...potentially into a cylinder.

 

Someone with more knowledge on the fuel pump can give a better description.

 

As a thought.... leave the petcock on for a night and see if the fuel level changes. Turn off the petcock the next night and compare.

[Semi-retired]

As a thought.... leave the petcock on for a night and see if the fuel level changes. Turn off the petcock the next night and compare.

Just changed the oil and filter.

 

For now......I think maybe I'll just heed your previous tip....and turn off the petcock when stopping; it's not as big an inconvenience as changing the oil......and not NEARLY as expensive as the alternative/consequences.

 

Perhaps I'll keep your "test procedure" in my back pocket for sometime when I'm due for an oil change anyway.

 

Thanks, bud!

[XV1100SE]

Another option for testing would be to disconnect the hose going from the fuel pump to carbs and run it into a container. Leave it for a night (with petcock on) and see if any fuel is in the container in the morning.

[DarkLeftArm]

First off, yes it is possible for gas to drain into the crankcase while parked. The way for that to happen is if you have an issue with one or more floats in the carbs. if the float vale is not sealing the gas can overflow, drain into the carb and from there drain into the cylinder, where is sneaks past the rings and into the oil.

 

If this is happening, starting the engine can be dangerous to the engine. IF it fires with one cylinder full of gas it will hydro lock and can damage the piston and/or connecting rod. So it is something to get right after to find if you have an issue.

 

As for testing the oil for gas. put a drop of oil on your finger. Smell it. You can smell the gas in the oil. Now rub that oil between your fingers compare it to a drop of new oil. If the drain oil feels thinner then it likely has gas in it. When you pour the oil from the drain pan into whatever container you put it into, pay attention to how much oil there is. If you have the same or more drain oil than what you put in, then you know something was added. Remember the filter will be full of oil. So you should always end up with less drain oil than the amount needed to fill to proper level.

 

I like these.

Also, rub the oil between your fingers ad then blow on it. If it's contaminated with fuel, the fuel will evaporate and make your fingertips feel cooler. Clean oil won't evaporate.

[cowpuc]

Also, if you remove the oil fill cap on your crankcase and take a quick sniff and you smell gas ya got a problem. Another test you might think about doing is keeping the bike parked on upright on a jack (or center stand if ya had one) and see if you accumulate fuel out of the overflows. As crazy as it sounds, I worked on a guys scoot one time for him who was having a similar problem and figured it out that his side stand had worn enough that the bike was leaning to far on the side stand, causing the floats to overfill the bowls and the overfill traveled thru the carbs and down the intakes instead of flowing out the overfill drains. Came right back to perfect after side stand repair..

Not sure if the Gen 2 have a vacuum line attached to the fuel petcock's (operating a diaphram shut off) but, if it does, it is also possible for that diaphram to go bad and fuel to flow thru the vacuum into the engine..

Just a couple more thoughts to entertain Semi, hope you figure it out brother!