I have a 99 Sportster XL1200, there is oil leaking from the engine vent tube, How can I fix this?

Talked to Harley service department they told me it was from changing to Synthetic oil; changed back to petro based same problem occures. I used synthetic oil for 2 years before this problem started. It is leaking from the hose behind the starter on top of engine case.I have a 99 Sportster XL1200, there is oil leaking from the engine vent tube, How can I fix this?
Okay the number one cause of this is overfilling with oil! Check your oil on level ground straight up(not on the sidestand, at full operating temperature. It does not have to be at the very top, I keep mine about halfway and have no trouble. What you were told about syth oil is crap, I have over 70,000 miles on my '96 883 and have run Amsoil 20-50 in it since 500 miles.


Very high humidity can also cause this blowback.


Your rocker boxes have what Harley calls umbrella valves, they are rubber one way valves intended to prevent the blowback you describe, over time they get hard and don't work 100%.


Finally have a compression leakdown test to see if you have ring or valve train trouble.


Do not vent to the atmosphere as suggested it makes a mess on the streets and causes your engine to produce more air pollution.I have a 99 Sportster XL1200, there is oil leaking from the engine vent tube, How can I fix this?
No problem. Nothing irks me more than when a bunch of people that haven't got a clue start giving advice. I have my Sporty and several Buells and do all of my own maintenance. I even did the warranty stuff myself.


The day after you see one of my bikes in a Harley service department it will be sold. Report Abuse

Just a suggestion you may want to check out


http://www.et-performance.com/faq.html Report Abuse

only thing I might add is check your air filter make sure it aint oily or dirty or wet
the hose you speak of, is it open to air? and has the stock breather been replaced? this is a common problem with sportys, and the normal solution is to run the hose to the ground and let the small amount of oil drip. this problem occurs due to the head breathing of all later model sportys. there is no positive fix for it. even the stock bikes will blow a little oil into the stock breather
Take it back to the Harley shop and have them put new seals in it. Its not the oil its the vibration of the motor that causes Harleys this problem.
Every Harley leaks, just get used to it.