Slight gas smell to the crankcase oil?

[Timotwo]

Hey all,

I'm prepping my 2008 RG for a big ride, starting in a couple days, and while checking the oil level, I detected a slight smell of gas. I just turned 47,000 on the engine (all mine so I know how the bike was treated) and my last oil change was at 45,000. I run Mobil 1 V-Twin (20-50) and have since I changed oil at the 1,000 mark. Any thoughts?...or am I just over-sensitive to the slight gas smell. I've never noticed it before.

Much obliged on any "thoughts" you want to share.

 

[knightster637]

Im not an expert on V-twins but I did work as a heavy equipment/diesel mechanic for a few years. On a diesel if you see or smell fuel in the oil it's sometimes caused by an ijector that is stuck open letting pressurized fuel squeeze by the piston rings. I suppose it could also be a ring failure also. Have you noticed smoke in the exhaust or any oil residue in the exhaust? You are not being overly sensitive, enough fuel in the oil will thin it out and cause a much bigger headache.

 

[NEWHD74FAN]

If your mileage is mainly in town riding, likely you are not riding long enough to evaporate the IC and moisture byproducts in suspension in your motor oil...! May be a hint that you are harder on your oil than you think.

 

[Timotwo]

Im not an expert on V-twins but I did work as a heavy equipment/diesel mechanic for a few years. On a diesel if you see or smell fuel in the oil it's sometimes caused by an ijector that is stuck open letting pressurized fuel squeeze by the piston rings. I suppose it could also be a ring failure also. Have you noticed smoke in the exhaust or any oil residue in the exhaust? You are not being overly sensitive, enough fuel in the oil will thin it out and cause a much bigger headache.

Good questions....No smoke in the exhaust and I just checked the pipes...no oily residue. Hmmmm...

If your mileage is mainly in town riding, likely you are not riding long enough to evaporate the IC and moisture byproducts in suspension in your motor oil...! May be a hint that you are harder on your oil than you think.

Fair comment here too...on this bike, no more than 8,000 are "around town" miles....(my guess). On the lighter side of the comment, here in 'Vegas, the engine is 110 degrees before you even start it!

I sure hope it's not a ring issue...I don't think I could get that resolved before Friday. I'm having a new set of tires put on in the next day or so...Maybe I'll have them do an injector test...unless you guys know of a quick way to test it that I can do. I haven't cracked the manual on this yet but I guess I'd better....

 

[Hoople]

Are you running a fueler or pulse stretcher. Have you checked for any codes.

 

[Timotwo]

Are you running a fueler or pulse stretcher. Have you checked for any codes.

Nope. No fueler or pulse stretcher. Standard Stage 1 kit air cleaner upgrade, Rush true duals and rush slip-ons (and dealer installed mapping). None of those changed for the last year though. Two years for the slip-ons and the Stage 1 air cleaner.

Just as an update, I keep checking the oil and smelling it (either I'm realling digging the free "high" or I'm trying to make sure it's not just me.) The oil is just slightly tobacco stained in color. It's by no means "new" but it's not even CLOSE to black. Historically I'm an "over changer"...change the oil every 3333 miles (gives me three oil changes in a 10K range opposed to two as the manual suggests). Just the last two changes did I go with the 5K change interval. I've read a few posts and figured maybe since I run a full synth oil, that maybe the 5k changes aren't so bad.

Oh, some more info is that I haven't noticed any measurable increase on the oil level stick either. I went for a couple hundred mile ride last Sunday and then road the bike to work (13 miles each way) 4 out of 5 days last week and then today. Maybe "NEWHD74FAN" has a point. Maybe I haven't brought the bike to temperature the last week or so. Although, it HAS been 100 degrees daily this last week. Hmmmm

 

[knightster637]

This bike doesn't have a carb by chance does it? What about a fuel shut off valve? I think your somehow leaking fuel past the cylinders while the bike is off, maybe a bad check valve. Also check the plugs for black/wet. You could be running too rich. But if it were running rich enough that fuel is getting by the rings and is noticeable in the oil I think it would probably be running very poorly and puffing black smoke. Check your plugs and as Hoople suggested check for codes.

 

[Hoople]

Nope. No fueler or pulse stretcher. Standard Stage 1 kit air cleaner upgrade, Rush true duals and rush slip-ons (and dealer installed mapping).

I know it is not an option, but you really need a sniffer to see how much unburned fuel is coming out the pipes. Take a look for any historical codes. O2 sensors that are pegged will be a dead give away.
Is your air filter clean? If you had a serious issue with the bike, I would think you would throw some o2 sensor codes or ignition codes.
It is really hard to say without knowing what the CO & HC values are.

Does the bike have rich exhaust tips? (black). Generally when an engine is really rich, you can smell it. How does the exhaust smell at idle. A new set of plugs never hurts either.

1) clean air filter
2) Codes
3) New plugs to help burn what is there.
4) exhaust tip color. A dealership download should not be black.

 

[maine-e-axe]

This bike doesn't have a carb by chance does it? What about a fuel shut off valve? I think your somehow leaking fuel past the cylinders while the bike is off, maybe a bad check valve. Also check the plugs for black/wet. You could be running too rich. But if it were running rich enough that fuel is getting by the rings and is noticeable in the oil I think it would probably be running very poorly and puffing black smoke. Check your plugs and as Hoople suggested check for codes.

Knightster/ no carbs after 06:s

 

[knightster637]

Knightster/ no carbs after 06:s

Ah good to know. Thanks. Still new to the Harley world