Nc700x gas smell in oil.

15mtyler

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A little background. After the first 600 mile service, I took a 300 mile round trip to tuscon az. The morning after I got back I checked the oil and noticed it was overfilled. Thinking the dealership overfilled it, I removed enough oil to bring it to where it's supposed to be, but I noticed the oil smelled of fuel. I took it to the dealership and their head tech said he smelled it too, and to do an oil change and see if it comes back. I changed the oil, rode it about 200 miles and got the same smell. So I took it back. I got a call the day after and the tech said the guy who does their engine rebuilds said it was the clutch causing the smell, and they adjusted it so it wouldn't do it because it was out of adjustment, but did not change the oil. The oil level isn't rising, but I still smell gas. Any thoughts?
 

670cc

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On a gravity fed carburetor type engine. fuel entering the oil is conceivable due to the carb float sticking open and fuel dribbling into the intake. On a fuel injected bike like the NC, the fuel would need to enter the engine by way of a stuck injector, and only when the bike is switched on and the fuel pump is running. In such a case,I would expect the engine to run horribly. This is a very unlikely scenario, but I suppose not entirely impossible.

There are parts of this story that are incomplete. Is the engine running normally? In the case of the clutch adjustment, was the clutch slipping prior to the adjustment? If the clutch was misadjusted enough to cause an odor, I would expect you would have experienced drivability problems.
 

jspivy

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I would get a sample kit from Blackstone, change the oil myself, and monitor the level. It's $28 to find out what's in the oil and if anything is above average for the engine (yours shouldn't be since it's not due for a change by mileage).

Standard Analysis – Blackstone Laboratories

Gas will burn off with time. So if it is gas, and the leak is stopped, the oil level should go down. But the oil is thinned by gas and I would change it.

I don't see how the clutch could change oil level.

The results from Blackstone will let you know if it is oil. Or coolant. Or water. Or... Take it to the shop and say "I have xyz in the oil."

Sent from my ASUS_Z01HD using Tapatalk
 

15mtyler

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On a gravity fed carburetor type engine. fuel entering the oil is conceivable due to the carb float sticking open and fuel dribbling into the intake. On a fuel injected bike like the NC, the fuel would need to enter the engine by way of a stuck injector, and only when the bike is switched on and the fuel pump is running. In such a case,I would expect the engine to run horribly. This is a very unlikely scenario, but I suppose not entirely impossible.

There are parts of this story that are incomplete. Is the engine running normally? In the case of the clutch adjustment, was the clutch slipping prior to the adjustment? If the clutch was misadjusted enough to cause an odor, I would expect you would have experienced drivability problems.

The bike runs and idles fine. The clutch was not slipping. The engagement was at the last 10 percent of the release, and after the adjustment, it is at 50 percent. Maybe it is leftover residue from breaking? The bike is a 2015 I bought with no miles. It has about 1250 miles on it now. And I have ordered a kit from blackstone labs.
 

670cc

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Stepping way back and looking at this situation again, the following observations could be made:

Dealer overfilled the oil. This is not at all surprising. Stop taking the bike to a dealer and service it yourself.

There is probably nothing wrong with the clutch and there never was. The dealer just did something easy to the bike to be able to send you on your way and out of their hair. Assuming you’re talking about a manual clutch, the adjustment is so simple a rider can actually do it while riding the bike. I’m not advising that, but just saying it can be done, and it’s certainly not something that requires dealer service.

As already pointed out, the rise in oil level could also be due to coolant in the crankcase. Is the coolant level OK?

Hondas are very reliable, and I have not heard of a case yet of fuel contaminated oil on an NC. I would monitor the oil level for awhile, go ride, and not worry about it much.
 
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Rapturee

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Hey 15M, if you are still concerned about the gas smell in the oil then change it again yourself. It is not that difficult and just may give you the piece of mind you need. An oil change is fairly cheap if the gas smell is still a concern. :{)
 

15mtyler

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Dealer overfilled the oil. This is not at all surprising. Stop taking the bike to a dealer and service it yourself.

There is probably nothing wrong with the clutch and there never was. The dealer just did something easy to the bike to be able to send you on your way and out of their hair. Assuming you’re talking about a manual clutch, the adjustment is so simple a rider can actually do it while riding the bike. I’m not advising that, but just saying it can be done, and it’s certainly not something that requires dealer service.

As as pointed out, the rise in oil level could also be due to coolant in the crankcase. Is the coolant level OK?

Hondas are very reliable, and i have not heard of a case yet of fuel contaminated oil on an NC. I would monitor the oil level for awhile, go ride, and not worry about it much.[/QUOTE]

Oil changes will be done by me from now on. Only reason the first one was done by the dealer was because it was the first service at 600 miles. On to the coolant. Coolant level is spot on, and is clean. No oil in the coolant reservoir.
 

MZ5

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You’ll essentially always have at least a tiny amount of fuel in the oil. That’s the nature of a gasoline engine. If you have an injector whose spray pattern is no longer optimal, you’ll get more fuel in the oil. Same if you have other mechanical or even electrical (spark) degradations.

Don’t waste your money on Blackstone Labs. They don’t measure fuel content. They measure flash point and infer an estimated fuel content. You have to have a lot of fuel in the oil before Blackstone picks it up, and even then they under-report it rather badly. If you want a decent fuel content report, use a lab that checks fuel content directly via GC.

Personally I wouldn’t worry about this until or unless the oil starts to smell rather strongly of fuel, or the level rises, or mpg declines along with fuel smell.
 

Jt105

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Be sure you are not screwing the dipstick in when checking the oil.
With the bike straight upright....
Unscrew. Wipe clean. Insert. Remove. Look at level on dipstick.

JT
 
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