r/sportster • u/Grizlum • 5h ago

PCV Oil

I have a 2006 sportster 1200 with 35k miles as my first motorcycle. I’ve rode it for about 3 months now. Whenever I ride more than 30-45 min I have a substantial amount of oil that leaks from the air filter. I usually have some spray down the side of the bike specifically on the oil reservoir. Sometimes a dark spot on my jeans

I’m 99% sure it is just age. More specifically pcv umbrella valves worn out spraying too much oil out or I’ve heard worn piston rings can put too much pressure in the crankcase causing more oil in the crankcase.

I just threw a catch can and a cheap eBay filter on for the time being, just to stop the oil spray. But I would like to go back to stock. Is there any recommendations to help with too much blow by coming out of the pcv? Or Is this normal? I’ve heard if a Harley isn’t leaking it’s not running. I just don’t know what is an acceptable amount. I have ordered some used pcv umbrella replacements, just waiting for delivery. Any tips help!

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u/matterlord1 5h ago

What air cleaner are you running? Some have better implementations than others for getting the oil back into the intake.

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u/Grizlum 5h ago

Had to look up via part number but appears to be an Arlen Ness? I should have phrased that better in the op. I have no idea if that is stock or not. I didn’t even think of the filter itself being the issue but seems to make sense

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u/matterlord1 5h ago

Yeah, some air cleaners will point a hose or nozzle directly into the intake stream and they don’t leak too much. Some air cleaners just rely on the air movement to get the oil moving in the right direction, they typically will leave trails.

It’s also not a bad idea to replace the umbrella valves, they’re pretty cheap and relatively accessible.

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u/oinkinstein 5h ago

I have open screened breather bolts on mine and there’s never any oil coming out. Mines got about 14k miles on it tho and I was recently in the rocker boxes and the umbrella valves looked good but often times peoples oil level is too high. Make sure it’s between the add and full line on the dipstick not at full. Check when hot.

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u/shaman-doser 4h ago

35,000 miles on a 2006 sporty is far from old. And the saying about oil leaks being normal are from years ago. Pre 84 Harleys were notorious for leaking, I’ve never had a problem with oil leaks that I couldn’t fix with a new o ring or a gasket. If you’re getting that kind of oil you probably start with the oil level, should keep it halfway between add and full. Don’t keep it full, and I’d recommend rerouting the breathers to an external breather setup. It’s easy and effective and definitely a better option than going back to stock. Your engine will be much more efficient with an aftermarket intake than the stock air box.