Air filter/carb question Harley Engine Discuss Air filter/carb question in the Harley Tech & Harley How-to forums; What the heck is that?! I removed my air filter to clean it, and a blop of yellow-brown oily goo spilled out onto the right side of my engine. There ...

What the heck is that?!
I removed my air filter to clean it, and a blop of yellow-brown oily goo spilled out onto the right side of my engine. There was residue inside the air filter as well, but nothing on the carb inlet.
A quick wipe with a shop rag cleaned it up, and I moved on to clean/reinstall the filter. I figured it was likely some oil spitting back through the carb, combined with built-up dust/dirt from the filter.
However, after running the bike for about 100 miles, I removed the air filter again and was rewarded with another blop of the stuff!
Any ideas as to the source of this gunk?

BTW--I'm riding a 2001 FLSTF, K&N air filter, 42mm Mikuni carb, .510 S&S gear-driven cams, 96 cu in stage II kit, V&H short shots pipes. I also put on an oil cooler, but the rest is stock.

It is the oil vapor/ mist in the engine's breather system condensing onto your air cleaner.
The breather system flows into the air cleaner housing to burn off the oil in an effort to control smog emmissions. Some bikes are just more messy at it than others. There are many aftermarket contraptions available that are supposed to reduce this un-wanted effect.
Many are touted as "the best" at reducing or completely eliminating the mess, but I cannot recommend one over the other.

Thanks for the info, dls8. I figured it was something "normal", as performance has not been affected. Good to know what it is, though. Thanks!

[Wrightturn]

A breather kit that runs a hose to a catch can or on the ground or garage floor keeps it off the bike. Yes, the EPA will be unhappy.

There is a breather in each rocker box that may need to be serviced.

[myt evo]

You can also increase the size of the hole in the breather bolts slightly which can eliminate or at least ease the the problem somewhat depending on how severe it is. And as Wrightturn said the breathers in the rocker boxes may need to be serviced.

[frisco-rigid]

Hey Rev

Man are you lucky-- the A-team,, the cream of our crop layed the 411 down on ya..

I route my breathers over to my chain but you- with a belt- might want to consider the catch-can or the various filters available that eliminate the purging into your intake altogether..

Great advice, gents! This is one of the reasons I love this forum--the voice(s) of experience.
I'll add that to my winter service checklist.
Thanks, y'all.

Aquick fix would be to check the oil level in your oil tank if you are at full or over that could be a source right there. bring your oil level down about 8 ozs. How? Use a turkey baster with a big rubber bulb on the end of it.