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Gas mixing with oil...

lilrich2u

Member
I havent rode my 2000 Dyna Wide Glide in about a month, then last week something a little odd happened.

I was coming back from a hour long drive, turned on my street to go home and the engine started acting like I was running out of fuel. I pull over to turn the petcock and for a microsecond, even with the clutch pulled in the bike acted like it wanted to keep running in gear. At the time with it being so cold I thought maybe I just pulled on the front brake lever instead of the clutch or something... it was freakin cold and I was a little braindead.

I switch the petcock over and the hesitation stops.. I drive home and everything seemed fine.

About two days later I see my bike leaking a TON of oil on the ground. Pull the dipstick out and there is a significant amount of gas that has mixed with oil.

So at this point my gameplan is to change out the oil, pull the carbs and check the float bowl and overall clean the carbs with cleaner. Im also gonna double check all the bolts and make sure everything is tight. Im just wondering if I have permanently lost a gasket someplace to cause the bad oil leaks or if the viscosity of the oil mixing with gas caused it and once I put new oil in there everything will go back to normal.

If anyone has any ideas or tips it would be highly appreciated. Im not a total newbie to bikes, but Im not a mechanic either.

Thanks and take care.
Rich
 
About two days later I see my bike leaking a TON of oil on the ground. Pull the dipstick out and there is a significant amount of gas that has mixed with oil.

Rich,

Was the level in the oil tank high when cold, i.e., close to or higher than the high level on the stick?

I have had my float malfunction and had gas leak out of the bowl and gas tank (yes, I know I am supposed to close the tank valve every time I stop!!) which definitely "washes" the bike and puts an oily mess under the bike. But the engine was not leaking oil, the gas was washing the oil off the engine and dripping an oily mess under the bike. With gas everywhere, if you pulled the dip stick it might seem like it smelled of gas too.

What I can not figure is how the gas could communicate with the oil unless there are some other serious problems that would make the bike run terribly.

We will have to see if other folks with carbed bikes chime in with this problem in the past and can enlighten us.

TQ
 
A lot of what you were saying totally rings true. Ive had a very slow leak since Ive owned the bike but could never pinpoint it.. from that the bike has always had oil underneath. So your theory that the oil on the ground was actually old oil that was washed off from the leaking gas totally makes sense.

The oil level when cold looked about average, but because the gas was mixing with the oil it wouldnt stick to the dipstick and hard to tell. There is definately gas in with the oil. The oil has the same consistancy as water and smells like gas on my fingers.

Im just hoping this entire thing isnt gonna be your typical "hd big job" where its a grand or more to fix. I love my bike but theres been a ton of little things that have gone wrong.

Any advice is greatly appreciated.
 
I used to religously turn off the petrol on my '99 FXDX and the 1340s before that because of exactly the problem you are having. A friend who was a HD mechanic said it wasn't worth the risk not to. By the sound of it he was right. Good luck with the oil change.
 
I have a 2000 dyna and have had NO problem with the gas to oil ....

It sounds like gas is LEAKING past the VACUUM OFF and PAST the carb.float needle valve.....(BOTH)

gas is on a vacuum basis when engine is running:engine draws vacuum to OPEN gas tank valve.....ONLY in off position is it OFF.
you must have a defective shut-off vacuum valve......(sticking open)

You also must have a TOO HIGH a float level or dirty needle NOT allowing gas to STOP when float-needle say to. No other way for gas to leak into engine unless BOTH vacuum valve and carb float shut-off are not working properly.

so I'd think BOTH are the problem...

You can always turn to OFF at the tank but ????? if you forget!!!

signed....BUBBIE
 
sportsters can suffer with this issue as well - it always pays to turn of the tap.
I would remove/strip and clean the carb just for good measure - remember to take note of how manys turns are on the mixture screw.
check the vaccumm lines from the petcock.
change out the oil and filter

Hobbit, you are right on! :) Had to do the deed on my brand "Y" metric back in 1992...but also had to rebuild the starter too, as it was flooded with oil and gas as well! :(


I have a 2000 dyna and have had NO problem with the gas to oil ....

It sounds like gas is LEAKING past the VACUUM OFF and PAST the carb.float needle valve.....(BOTH)

Gas valve is on a vacuum basis when engine is running: engine draws vacuum to OPEN gas tank valve.....ONLY in off position is it OFF. You must have a defective shut-off vacuum valve...(sticking open)

You also must have TOO HIGH a float level or dirty needle NOT allowing gas to STOP when float-needle says to. No other way for gas to leak into engine unless BOTH vacuum valve and carb float shut-off are not working properly.

So I'd think BOTH are the problem...

You can always turn fuel petcock to OFF at the tank but ??? if you forget!!!

signed....BUBBIE

Bubbie, you get the bells and thumbs up from me! :bigsmiley12:
 
A lot of what you were saying totally rings true. Ive had a very slow leak since Ive owned the bike but could never pinpoint it.. from that the bike has always had oil underneath. So your theory that the oil on the ground was actually old oil that was washed off from the leaking gas totally makes sense.

The oil level when cold looked about average, but because the gas was mixing with the oil it wouldnt stick to the dipstick and hard to tell. There is definately gas in with the oil. The oil has the same consistancy as water and smells like gas on my fingers.

Im just hoping this entire thing isnt gonna be your typical "hd big job" where its a grand or more to fix. I love my bike but theres been a ton of little things that have gone wrong.

Any advice is greatly appreciated.
Just remember that when your bike is leaning on the kick stand that when your float and needle stick that the gas will run first down thru the intake and into the cylinders and go around the piston rings. I have seen this happen many times and even a full tank of gas, it litteraly started to run out of the dipstick itself. This can even happen on softails as well but the gas will only fill the engine sump untill you try to start it up, this could be a dissaster.
 
"but the gas will only fill the engine sump untill you try to start it up, this could be a dissaster."

Thank you very much for the advice btw.

Just wanted to clarify something from what you said... should I be doing something more than changing the oil and filter before I try and start it up?

Dont know if you meant it would be a disaster if I tried to start it as is, or if there is more I should do than the oil/filter change.

Thanks again,
Rich
 
I think if it was me I would buy some cheaper brand oil and filter, change it and run it for a 10 minutes and then change it again with some good oil just to make sure to get it all out.
 
I think if it was me I would buy some cheaper brand oil and filter, change it and run it for a 10 minutes and then change it again with some good oil just to make sure to get it all out.

Thats exactly right just buy some cheap no name oil to flush the system out. Your dyna has the oil down below the trans so when the gas leaks through it will mainly be in the oil pan, there would only be about a half a qt in the sump as for the softail it has an oil tank mounted up highso the engine would be full before the gas would show up in the oil tank until you tried to start it up. Dont forget to take care of that carb problem, it could be a small piece of trash thats got the needle valve hung open. Hope this helps.
 
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