Oil Smells Like Fuel

Tigerkf

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I recently changed my spark plugs and now it was time to change the oil. I drained the oil and found that it smelled like gas. I guess this means the engine is running too rich. Has anyone else experienced this? Is it possible one of the plugs is not firing properly and not burning all the fuel in that cylinder? I searched the forum using many different variations but did not find anything related! Thanks for your help. By the way it's a 2018 with 16,000 miles on it!
 

Tigerkf

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Thanks Tenman! Does anyone have any other suggestions that might help me diagnose this problem?
 

Squibb

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The human sense of smell can deceive, so it might be an idea to get the oil tested if you can in these strange times. Maybe get the codes read (OBD2 reader/dealer).

Fuel leak-down, creating oil dilution is a major concern - for me, it suggests a leaking injector, but it seems very unusual for a 2018. It usually manifests itself at a cold start, sluggish to fire up, maybe a puff of black smoke, erratic tick-over until warmed up.
 

Jlq1969

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How many miles does the oil have? ... Do you make many miles in transit through the city?
 

Tigerkf

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Oil had 3K to 4K miles on it. I haven't ridden a lot this last month but have started it a few times. Most of my rides are on the highway. There are no lights on indicating a code and the engine seems to run fine.

Most of my rides are at highway speeds. The engine starts fine and doesn't seem to run rough. I checked the oil again this morning and it's definitely fuel smell, my nose is not deceiving me.

I talked to a friend who is a mechanic at Ford since 1979. He told me that I'm reading way too much into this. He asked if the engine was running rough or if it was hard to start and I told him it wasn't. He said he wouldn't go chasing causes until I know there is a problem. He said if the fuel mixture looks good when you put the bike on a scanner (diagnostic tool) then he doesn't think there is a problem. He said all engines get a certain amount of fuel into the crankcase. The more short rides and cold starts you do contribute to this.

I will probably have the dealer put it on the scanner when I take it this week to have new tires installed. If it doesn't show any codes and the fuel is in spec, I will just ride on and monitor the oil for fuel smell. I will try to update you guys with any developments.
 

EricV

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I agree with your mechanic friend. ;) The key here is in this sentence:
I haven't ridden a lot this last month but have started it a few times.
Stop starting the bike and not riding it. Every time you do that you're running the cold start cycle and even if you're running it for a while, it's not the same as riding the bike. This is why you smell gas in the oil. Buy a maintenance charger like an Optimate or Battery Tender, plug the bike in and leave it until you're ready to ride.
 

Tigerkf

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I agree with your mechanic friend. ;) The key here is in this sentence:

Stop starting the bike and not riding it. Every time you do that you're running the cold start cycle and even if you're running it for a while, it's not the same as riding the bike. This is why you smell gas in the oil. Buy a maintenance charger like an Optimate or Battery Tender, plug the bike in and leave it until you're ready to ride.
Thanks! What I'm reading into your statement is to start riding more. I'll just ignore the trickle charger idea because that insinuates not riding for a while!

1590004439117.png
 

EricV

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I hope that works for you. But if past performance is any indication, you don't always have time to ride as often as you would like. A Maintenance charger is not expensive and helps the battery last longer as well. I used to ride more than most and used a maintenance charger anyway. I've gotten 9 years from a battery with no indication of faults or weakening. I used to average 25-50k a year, but sometimes the bike would sit for a few weeks too.

The real point here is ride more or not, but don't just start the bike and let it run w/o going for a ride and really getting it to full operating temps under riding conditions.
 

14kmtnman

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I had that same issue twice. It turned out to be injectors both times. I wound up buying 2 new ones the first time. The second time I had all 4 (2 spares) professionally cleaned and tested for $50, I think. The 2nd time around I also changed the in tank tea bag fuel filter and the pump. The reason for doing both was how dirty the filter and the inside of the lines were. I was very surprised that the inside of the tank was clean as a whistle when I took everything apart. I also added one of those in tank Guglatech bag filters as an extra precaution. I have no idea where all of the dirt came from. I always use tier 1 gas when I can. There are links on this site for the exact replacement teabag filters. I just used one of the ones that came with the pump. There is also a built in filter in the pump that should be backflushed at the same time everything else is apart. The whole process is not too hard. You just need to be careful with some of the plastic pump parts.
 

ballisticexchris

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I agree with your mechanic friend. ;) The key here is in this sentence: "I haven't ridden a lot this last month but have started it a few times."

Stop starting the bike and not riding it. Every time you do that you're running the cold start cycle and even if you're running it for a while, it's not the same as riding the bike. This is why you smell gas in the oil. Buy a maintenance charger like an Optimate or Battery Tender, plug the bike in and leave it until you're ready to ride.
That is an interesting assessment. I have never heard of it before.

I have been unable to ride my bikes or drive my truck for months. I start everything up at least once every few weeks and let them idle and vary the rpms for at least 20-30 minutes. Beta, Super Tenere, and GMC truck are all ran up to temperature until the fans kick on and off a few times. No unusual gas smell in the oil at all.

I have been doing this on every motor vehicle I've owned throughout my adulthood (that cannot be driven/ridden). I also put fresh fuel/stabilizer and a fresh oil change before they are left dormant. Everything is on battery tenders. After I'm ready to ride I do a fresh oil change. With my 2 strokes I change the plug as well when it's time to take it out of storage.
 

Cycledude

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I recently changed my spark plugs and now it was time to change the oil. I drained the oil and found that it smelled like gas. I guess this means the engine is running too rich. Has anyone else experienced this? Is it possible one of the plugs is not firing properly and not burning all the fuel in that cylinder? I searched the forum using many different variations but did not find anything related! Thanks for your help. By the way it's a 2018 with 16,000 miles on it!
Did you check the oil level in the window before you drained it ?
i do agree with Eric it’s a bad idea to be starting the bike and not riding it.
 

Sierra1

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. . . . I used to ride more than most and used a maintenance charger anyway. . . .
Same here. Battery on the 'Tender. . . . STA-BIL in the tank. . . . nothing to worry about. If I know that I'll be able to ride consistently, I won't use the stabilizer. Always the 'Tender at the end of the day though. :)
 

taskmaster86

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You can't tell if you have real fuel dilution just by smelling your oil. You would need to send a sample off to a lab and they will evaluate if you have real fuel dilution or not.

Motor oil smelling of fuel is generally normal and usually does not cause a problem. When you go for longer highway rides, the engine and oil will heat up so much that the fuel that is in the oil will be evaporated and burned away.

The main reason why all modern engines have PVC or crankcase ventilation systems is because there is almost always a mixture of water, fuel and oil being vaporized in the crankcase as the oil sloshes around and the engine operates. A breather or PCV system allows the vaporized contaminants to be purged out of the crankcase while the engine is running. Most of these systems route the contaminants back into the intake where the mixture will be safely burned off.

I am not exactly sure what the crankcase ventilation system looks like on the super tenere or how well it really works but almost every motorcycle (almost every engine for that matter) I work on including the super tenere has oil that is very black and does smell slightly of fuel.

Anyways, the solutions to this issue are to try to take more frequent, longer highway trips, change your oil more frequently, send your oil off to a lab for analysis and to add a well proven fuel system cleaner to your fuel every so often in order to keep your fuel injectors clean and operating properly.
 

14kmtnman

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Talking about the oil level, my oil level would change over night from the leak down, leak thru. After a few days or so, the level would go from half glass to full glass. So yes you can smell the extra gas in the oil.
 

Sierra1

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. . . . Anyways, the solutions to this issue are to try to take more frequent, longer highway trips, . . . .
Back in the day, the Shell Answer Man advised that you had to drive at least 10 miles for the engine to warm up enough to evaporate the water in the oil. Now, that was also in the days of carbs, and early cats. Modern engines warm up much quicker. But, he's right, idling is not the same as driving/riding. :)
 

Tigerkf

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So to update you guys, I changed the oil and noted the oil level as mid glass. I went on a ride and it appeared that the oil level rose a little but was still an acceptable level. I did another ride and let the oil settle. The oil is now above the glass. Houston we have a problem! I spoke with a guy, a friend knows, at the dealer and he said the mechanic said there is a known problem where the ECU still sends power to an injector with the key off. Their solution will be to replace the ECU. Thank goodness I bought the extended warranty. I wish it were something simple but I don't think it is! I will be taking it to the dealership tomorrow!
 

gv550

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ECU failure is definitely not a known problem with the Super Tenere. Even if the injector was held open with the key off, there would be no fuel flow without the fuel pump running. If an injector is stuck open the engine would run terrible and roll black smoke out the exhaust, if in fact you could get it to start.
The oil level can be difficult to check, follow the procedure in the owners manual.
 

Jlq1969

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So to update you guys, I changed the oil and noted the oil level as mid glass. I went on a ride and it appeared that the oil level rose a little but was still an acceptable level. I did another ride and let the oil settle. The oil is now above the glass. Houston we have a problem! I spoke with a guy, a friend knows, at the dealer and he said the mechanic said there is a known problem where the ECU still sends power to an injector with the key off. Their solution will be to replace the ECU. Thank goodness I bought the extended warranty. I wish it were something simple but I don't think it is! I will be taking it to the dealership tomorrow!
The oil level is perfect. That is the correct way to measure oil. Handle it for a long time until the oil is very hot, stop it and measure it on the center stand. You don't have a problem. Leaving it idle until the water reaches its maximum temperature (as the owner's manual says) does not mean that the oil has reached a good temperature for the level measurement to be correct. The best way to measure the level is as you did on your second ride. You have no problem. Just drive it....and stay away from who told you that the ecu keeps sending power to the injectors with the key off .... stay away
 
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