Topic: Identify gunk on dipstick?

[stevenmac]

Checked my oil today and found this yellowish gunk on the filler cap. Anyone seen this before?

[Fritz]

That's an emulsion of oil and water. I've seen this in my bike on very cold days, probably caused by condensation.
It will dissapear after riding the bike long enough to let the water evaporate.

[bjbuchanan]

Yeah its just condensation. There was a guy with a detailed thread of the stuff he tried to do to get rid of his "chocolate milk"

It is normal especially with the cold weather. Just make sure you have the breather hoses/pvc stuff routed correctly or it gets worse

[stevenmac]

Thanks, guys. That makes sense.

[Duke McDukiedook]

Go on a decent longer ride (more than 30 min.) at least once a week to burn off the condensation during the cooler months.
 

[TwoTired]

Yes.  That is condensation or water in your oil.  It' not a good thing, and you should shorten the oil change intervals with it's presence.  However, the only way to avoid it is to get all parts of the oiling system above 100 degrees F or so (particularly where it collects the emulsion) and hold it there long enough for the water to evaporate out of the oil.

Short trips and/or cold weather make this emulsion far more likely to appear.

Cheers,

[stevenmac]

Well I'm about to take first ride of year (was sick for most of January). I'm willing to bet that winter in Seattle will make this emulsion pretty damn likely. TT: when you say it is not a good thing, what's the concern exactly? Thanks again.  -S

[TwoTired]

TT: when you say it is not a good thing, what's the concern exactly? Thanks again.  -S

Two issues.
One is that water doesn't lubricate nearly as well as actual oil.

The other is that the oil is organic in nature, and the addition of water promotes the formation of amino acids, which as the name implies, can dissolve metals.

Having acid oil is not a good thing.  Of course, the strength and quantity of the acids relate to how much metal conversion, or etching, occurs.
This is why the oil change interval is increased with the observance of water in it.  Time is the enemy.

Cheers,

[flybox1]

get yourself whatever cheap oil you want (i say cheap as its going to get recycled immediately), enough for one oil change, and enough of your preferred oil, some seafoam, and 2 oil filters...
run your bike, get it hot, drain the polluted oil and change your filter.
fill with the cheap oil you bought, a bit of the seafoam.  go for a ride.  get your engine hot....
drain the oil.  let it drain overnight even.  you want any remnants of the mayo do be gone.
change the filter.  add your preferred oil.
shouldnt happen again if you don't let your bike sit for so long. go for longer rides 

[Rigid]

Antifreeze? Oops, wrong forum.   

[Damfino]

I hate getting gunk on my dipstick. Usually means a trip to the doctor for a shot of penicillin...