Air Filters and Oil Drips et al -

I have seen several questions concerning engine oil dripping from air filter housings. I even asked a similarquestion after I got my 1995 XLH883.

Thanks to this forum I am now aware of the vent system including the underframe hose that must be kept straight and the backflow check valve.

In the "For what it's worth department", I ride my bike hard and fast, or sometimes a little faster even. I have NOT had a serious "dripping" out of my air filter since I started letting the engine idle for about 2 minutes after coming off the freeway ripping down the main drag, and whipping in to my driveway rather than shutting it down right away. That little bit of time seems to allow all the oil to get where it's supposed to go and not "burp" out of the air filter housing!

I hope this makes sense and it isn't just my imagination. I haven't had to wipe oil off my right side for several months now.

I hope this helps somebody

Same Oil Drip Problem

I have the same oil drip problem on my 2005 Ultra. On a 6000 mile trip ( hi speed ) that I take each year I carry an extra air filter so I won't have to try and clean the filter in a motel trash can. Mine starts to drip at about 2500 to 3000 miles of hard riding. I will give your suggestion a try. Thanks

I have an 02' Heritage Classic with an SE Breather and V&H True Duals and I don't baby it, I ride it hard. I probably shouldn't even mention this because as you know soon as you do shi% happens. But here goes, I haven't had a single run, drip, or error anywhere on this bike. Every time I inspect the air filter, it along with the inside of the air cleaner cover is as dry as a popcorn fart. :roflmao:

Don't know if it makes a difference but I have run synthetic in it since it had 1500 miles on it. I religiously change the fluids. Crank case at 3K, primary at 5K and tranny at 7500 miles. Also seems I don't here as many complaints about oil puking on the 88B's as I do with the 88's.

ringo 912

I am using a K&N Air Filter with RH Tru Duals. I have been using HD synthetic oil since my first1k check. As long as I perform my 5K oil changes I don't have any problems. I'm using synthetic oil in engine, primary and tranny. As I said before on the 6000 mile runs is where I have my problems, I never have any oil changes on the road as you never know what kind of dealerships you are going to run into. I've had to have some repairs done on the road, you can run into some good shops but I've hit some lousy ones too. thanks for reply.

Blowby is a inherent design issue with the Harley Engine caused from the turbulence created by the downstroke of the piston in the crankcase. Less restrictive air cleaner, any mods, how the bike is ridden (more likely with longer trips at higher sustained rpm's), oil level, all play a part in why it can be different from bike to bike. Type of oil and oil changes are irrelevant. Usually not noticed with stock air filters becuase they are so restrictive, the vacum created at the intake pulls any blowby back into the engine.

ReeseSS

Thanks for the reply, at regular maintenance intervals at home I don't have the problem but when cleaning the air filter there is minor amounts of oil at the bottom of the filter and cover. But no drips on the bike. Since the K&N filter is after market plus running at constant speeds of 75 - 80 MPH I guess I'll have to live with it on the long trips.

There are two fixes, the S&S reed type valve that installs under your oil pump. Or "The Cure" by Doherty. The S&S costs less, but is more labor intensive to install, the cure you only have to pull the head cover, but costs much more.
The vavle re-routes the turbulence so it does not interefer with the oil being able to return and overwhelm the breather. The cure is a better designed breather that resist getting overwhelmed.

you can also drill out the holes in your banjo bolts that bolt your air cleaner to the heads

Be careful with drilling out the banjo bolts. It leaves less metal in the bolt walls and when your wrist torque-o-meter has it's heavy days you find a two piece banjo bolt and a head drilling operation. If the oiling problem is excessive you might have an improperly aligned oil pump.

The problem is oil getting past the breather. Once it is past the breather it comes out the vent through the banjo bolts so making the banjo bolts vent hole bigger will not help. What does help is drilling the oil return hole larger under the breather so oil can return to the case easier.

theres an article somewhere about this, I'll post it as soon as I find it. its the cross holes not the bore of the hole so venturi vacuum pulls the oil in better.it worked for me