Oil Level & Blow By

G

Guard

New member
The older bikes this one way valve was metal, the newer ones are rubber or plastic which is what my 04 is. I guess if it was really blowing oil and the exhaust was not putting out blue smoke this valve could get bard and crack. One of my rubber vent tubes did this at 35K. Note the warning about flutter and also not running vents
 
There's a revision to the breather assy. in the heads for '11 that can be retrofitted to earlier bikes. HD must have recognized the problem.

FWIW when my bike is full of oil, my A/C drips. When it's at 1/2 full, it does not drip any more, but there's oil in the intake.
 
I had the same issue of oil on the bags and wifes right leg on my 02 ultra. I found that it was coming from the mister. I replaced the filter element and went with standard 1/4x20 bhcs and the leak went away. I would recommend checking your seal if it is not tight then the oil mist will not be pulled into the throtle body and just collect on the inside of the cover to be flung by the wind as it drips.
 
I don't know about these newer engines but, what you are describing is called blow by. It is from the displacement of vapours from the cylinders when the pistons decend. The 'air' is forced through the pinion side bearing into the cam case and then up the push rod tubes to the heads. From there through the 'maze' of the head and 'separator' valve in the head then to the AC. This is the normal path but with a larger engine and at highway speeds for extended times the system gets over powered, hence the oiling. It may be possible that your cam chest is loaded with too much oil and is adding to the problem. There is a 'reed valve' device which can be installed behind the oil pump to help reduce this 'fault'. The shovelhead vented this oil mist to the rear chain and was not noticed too much. Panheads vented to the primary chain and then to the street. Cars and trucks do the same but it is not such a big deal with them.
There are a few things that you can do to address this if it becomes too annoying. One is the 'reed valve' previously mentioned. That requires removing the cams and oil pump. The 'Valve' will NOT fit the 'B' balanced style engine found in some model HDs. You will have to find a qualified mechanic to help you with this work.
 
Guys........ normal engine oil operating temp is 230+ degrees.

A trip to the store or around the block won't get the oil close to the proper operating temp, sometimes on a cool day the oil will never reach the 230 degree operating temp. If you keep the oil at the full mark without it reaching the proper operating temp when it gets to the proper operating temp it may blow out when it gets hot, expands and foams due to overfilling.

So, as the manual says fill with 3 1/2 quarts of oil, or halfway on the dipstick COLD then check it when it reaches the proper operating temp and you will find at 230 degrees it is almost on the full mark.

Also if the breather tubes on the air cleaner are not installed correctly oil may blow out as well.

What I do is fill with 3 1/2 quarts of oil COLD. I have an oil temp gauge so I get the oil to the proper operating temp on a long ride on a hot day, let the bike idle for 1 minute per the manual, shut it off and let sit for a minute, then check the oil, add the small amount of oil necessary to bring it to the full mark. Next morning when the bike id COLD I check the dipstick COLD, and mark the dip stick with a sharpie (after cleaning it with mineral spirits). Then next time I fill to my cold mark and know when it gets hot it is not overfilled.

I can assure you unless you have a oil temp gauge you most likely will overfill because most folks always want the oil to be on the full mark, unfortunately it is done with the bike not to the proper operating temp, oil gets hot foams because it is overfilled and has to go somewhere usually out the air cleaner. That's why Harley says start with 3 1/2 quarts. COLD !!
 
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