Gas in Oil-- How?

[crankshaft]

I have an '07 with about 12K on it. I had it into the shop in March for 12K maintenance and oil change. After riding it about 500 mi. I noticed it was smoking like a crop duster. After checking the oil it looked as if it was overfilled. I drained about 3/4 of a quart to get it back to normal levels but it was still smoking. I also removed my PC3 just to eliminate that from the problem. Still have an issue with smoking. I called the shop and took it in. They claimed they found gas in the oil and attribute it to short trips. I've had this bike since June of '08 and ride it back and forth to work (7mi) one way and have never had this problem until this year.

I got the bike back last Friday and put a piece of tape marking the oil level to see if gas is getting in the oil with it just sitting there. I haven't ridden it. Luckily I have a VTX1300 that I can ride while I go through this with the FJR.

What could be causing me to get gas in the oil? Could short trips actually be the cause? And could someone explain why short trips could cause this. Also what can I do to prevent it?

 

[RaYzerman19]

I would normally think of this as something that can occur in cars moreso than bikes, but here goes the theory. When cold, the fuel mixture is rich and leans out as the engine warms up. Raw fuel can go past the rings into the crankcase, and therefore run into the oil. When the engine gets a sustained run at full operating temperature, the gas will evaporate and be burned off through the crankcase ventilation system. If the engine never gets to operating temperature or doesn't get sustained runs at full temp, the fuel will simply accumulate in the oil. You definitely don't want your oil diluted with fuel.

So, I'm a little unsure how much fuel is in your oil, nor do I know how rich your PC3 fuel map is, but since you're only running 7 miles, you definitely need to get out more on longer runs, say an hour at highway speeds a couple of times a week, maybe more.

 

[Geezer]

Do you notice any difference in the way the bike runs other than the smoke?

As Ray said, the gas has to be getting past the rings in order to get into the crankcase. If you are getting a lot of gas in there then you may have stuck rings on one or more cylinders.

 

[motodave]

or a stuck injector or two, bleeding and leaking when should be closed. run some injector cleaner and see if it clears up, if it doesnt you may need the injectors removed and inspected

 

[Constant Mesh]

When the engine is cold some of the gas injected into the cylinders condenses on the cylinder walls and ends up getting past the piston rings and down into the lower engine and the oil. When the engine is started cold extra gas is injected to overcome this condensing phenomenon so it's accepted that some gas will end up in the oil.

If you ride long enough the engine oil gets up to full operating temperature and the gasoline in the oil will eventually vaporize, leaving the oil and finding its way back into the air filter box and then be drawn into the cylinders and burned. So it's self correcting if the oil stays hot long enough to vaporize the gasoline.

You could have an abnormal quantity of gas in the oil if a fuel injector's solenoid valve didn't completely close when the engine's shut down. This would allow gas to enter a cylinder if the intake valves are open and it would make its way past the piston rings into the oil below.

 

[SwollenRaccoon]

That's a good and probable explanation. Here's what happened to me 17 or 18 years ago....

I had an '82 Seca Turbo that started getting gas in the oil. The problems were 1) A fuel petcock with internal leaking o-ring, and 2) At least one failing float in the carburetor float bowl. So....

The gas leaks past the fuel petcock when the petcock is in the "off" position. Then, when the fuel reaches the carb float bowls, the bowls should fill to a level that will allow the rising float to shut off fuel flow to the carburetor. However, I had one carb with a leaking float, so the fuel flow would not stop filling the failing carb. It fills to the point of overflowing, running down the cylinder wall to the crankcase.

I rebuilt the petcock and 4 carbs, and never had an issue after that. Thankfully, Yamaha had the parts available, but back then, the bike was only 10 or 12 years old. AND, that bike was carbureted. So I know the above explanation is irrelevant.

Make sure you change that oil, after you fix the problem, and then do it again after a few hundred miles. That gasoline can't be good for things like crankshaft bearings and the like.

 

[frito1]

Any gasoline engine is gonna have some gas in the oil. Should it be enough to raise the oil level? No way! Sending a sample to https://www.blackstone-labs.com/free-test-kits.php would let you know exactly how much is there.

But, if you have enough gas to raise the oil level you have an issue that could prove fatal to your engine.

 

[crankshaft]

Do you notice any difference in the way the bike runs other than the smoke?

As Ray said, the gas has to be getting past the rings in order to get into the crankcase. If you are getting a lot of gas in there then you may have stuck rings on one or more cylinders.

Yes the bike starts running like a dog and starts stalling at stops unless I keep up the rpms by using throttle.

 

[crankshaft]

or a stuck injector or two, bleeding and leaking when should be closed. run some injector cleaner and see if it clears up, if it doesnt you may need the injectors removed and inspected

I'll give this a try. Should I just use Sea Foam or Techron?

 

[lharrell79]

So you're saying the bike was perfectly fine before you took it in, and after you got it back it started having problems?

Lucas

 

[crankshaft]

So you're saying the bike was perfectly fine before you took it in, and after you got it back it started having problems?

Lucas

I knew I needed and oil change and I had a slight knock/ping so I wanted them to check the cam chain tensioner to see if that was the cause. I also had them do the 12K maintenance. Other than that no problems. They said my knock was from dirty oil, I was a little over due for an oil change. Maybe 1000 miles over. I was trying to make it to the end of the season and due one oil change at the end of season.

 

[lharrell79]

So you're saying the bike was perfectly fine before you took it in, and after you got it back it started having problems?

Lucas

I knew I needed and oil change and I had a slight knock/ping so I wanted them to check the cam chain tensioner to see if that was the cause. I also had them do the 12K maintenance. Other than that no problems. They said my knock was from dirty oil, I was a little over due for an oil change. Maybe 1000 miles over. I was trying to make it to the end of the season and due one oil change at the end of season.

Ok, going 1000 miles over your oil change isn't going to make a bit of difference. Dirty oil can make a knock, rattle, but it would be constant with the revolutions of the motor, and the oil would have to be really old and dirty. You're might be hearing ping from poor quality gas, high heat, and hard acceleration. I get ping under acceleration often. I attribute it to 87 octane, and 105 degree heat we've been having in TX.

That much extra gas in the crankcase because of short trips is silly, and they are making that jazz up. If you've truly got that much gas in your crankcase, then it's because of a stuck injector that is spraying fuel wildly, or you've got a cylinder that's not getting spark. A stuck injector is unlikely on a modern bike like the FJR.

I think the most likely scenario is that they just way overfilled your bike with oil. This would get oil into your cylinders, and therefore you would be burning oil (white smoke). Furthermore, burning oil would also mean that you most likely "oil fouled" your plugs. If you completely snuffed out a plug, and it's no longer sparking, then yes, you will be adding raw gas to your crankase.

I would highly recommend doing another oil change yourself, and changing the plugs yourself. If you don't have the ability or time take it back to the shop and try to get them to do it for a discounted price. Or try to find a local board member that can help you. Where do you live.

Lucas

 

[crankshaft]

So you're saying the bike was perfectly fine before you took it in, and after you got it back it started having problems?

Lucas

I knew I needed and oil change and I had a slight knock/ping so I wanted them to check the cam chain tensioner to see if that was the cause. I also had them do the 12K maintenance. Other than that no problems. They said my knock was from dirty oil, I was a little over due for an oil change. Maybe 1000 miles over. I was trying to make it to the end of the season and due one oil change at the end of season.

Ok, going 1000 miles over your oil change isn't going to make a bit of difference. Dirty oil can make a knock, rattle, but it would be constant with the revolutions of the motor, and the oil would have to be really old and dirty. You're might be hearing ping from poor quality gas, high heat, and hard acceleration. I get ping under acceleration often. I attribute it to 87 octane, and 105 degree heat we've been having in TX.

That much extra gas in the crankcase because of short trips is silly, and they are making that jazz up. If you've truly got that much gas in your crankcase, then it's because of a stuck injector that is spraying fuel wildly, or you've got a cylinder that's not getting spark. A stuck injector is unlikely on a modern bike like the FJR.

I think the most likely scenario is that they just way overfilled your bike with oil. This would get oil into your cylinders, and therefore you would be burning oil (white smoke). Furthermore, burning oil would also mean that you most likely "oil fouled" your plugs. If you completely snuffed out a plug, and it's no longer sparking, then yes, you will be adding raw gas to your crankase.

I would highly recommend doing another oil change yourself, and changing the plugs yourself. If you don't have the ability or time take it back to the shop and try to get them to do it for a discounted price. Or try to find a local board member that can help you. Where do you live.

Lucas

I'm in Dayton, Ohio. I can change the oil and have before. But I haven't gotten into the engine to change the plugs. Are they easy to get to?

 

[mcatrophy]

Couple of points -

My experience of short runs - 3 mile each way commute, sometimes for several weeks with no other riding, sometimes in very cold weather - is that there is no appreciable change in oil level between 6000 mile oil changes (as we do in the UK).

If your bike is smoking, the colour of the smoke says what it is:

• White is usually steam, i.e. water either from a cold start (very thin and short lasting) or a blown gasket leaking coolant into the cylinders,
• Blue is usually oil,
• Black is excess fuel.

This colour may help diagnose what is really wrong (like the mechanic who worked on your bike?).

 

[mdisher]

I'm in Dayton, Ohio. I can change the oil and have before. But I haven't gotten into the engine to change the plugs. Are they easy to get to?

Good lord no, neither is hard.

I'm south of you, and have a buddy with a really nice garage for stuff like this in Dayton. Pick up some plugs, oil and filter, PM me and we can work out a time to do both.

The biggest issue with the plugs is you need a really thin-walled socket to get them out, that's it.

-MD

 

[lharrell79]

There you go, MD's willing and has the knowledge, and you'll get to make some new friends. I would start with complete oil change, new plugs, check the air filter, and check the coolant level. I suspect an oil change, and new plugs will sort you out. If there truly is gas in your crankcase, you should be able to smell it when you change your oil. Or you can remove the oil filler cap, and sniff the hole. :blink: :blink: :blink: :blink:

Lucas

 

[crankshaft]

I'm in Dayton, Ohio. I can change the oil and have before. But I haven't gotten into the engine to change the plugs. Are they easy to get to?

Good lord no, neither is hard.

I'm south of you, and have a buddy with a really nice garage for stuff like this in Dayton. Pick up some plugs, oil and filter, PM me and we can work out a time to do both.

The biggest issue with the plugs is you need a really thin-walled socket to get them out, that's it.

-MD

Cool! Thanks!

 

[Pepperell]

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• The thin-wall socket for plugs is in the stock tool kit.
  

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• Craftsman PN 43324 Spark Plug Socket; $3.99. Fits front axle if you use it backwards.
  

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• While you're there get Craftsman PN 25702 6 piece Torx Bit Set; $9.99 for the security screws on the bag locks.
  

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• Prices are from a few years back, tho.
  

 

[72Duster340]

Use the Techron, it is a great product, I have seen it work cleaning dirty injectors in automotive applications. I use it about once a month as preventative maintenance in all my vehicles including the FJR. The Seafoam has a fair amout of alcohol in it, pump gasoline has more then enough alcohol in it already you don't need to add any extra. If your problem is a dirty injector leaking it should help cure the problem.