Moroso Air/Oil Separator V-Twin Universal Breather - Harley Touring, Softail & Dyna
About Moroso
Moroso has manufactured racing components in Connecticut since 1968, supplying engine, chassis and shop products developed through motorsport.
The Moroso Air/Oil Separator is engineered to keep crankcase vapors, oil mist, and moisture out of your Harley-Davidson's intake system. Unlike factory breather setups that recirculate contaminants, this separator ensures only clean air enters your engine. Its smart design prevents oil from ending up on your bike or the ground.
Why riders pick this
- Filters crankcase vapors and oil mist for cleaner intake
- Reduces engine detonation and knock
- Two-piece canister for simple cleaning and service
- Internal venting prevents oil mess
- Made in the U.S.A
This Moroso air-oil separator is a crucial upgrade for any V-twin owner looking to maintain engine longevity and performance. By effectively filtering out harmful crankcase byproducts, it helps reduce detonation and knock caused by a contaminated intake charge, leading to a smoother running engine and more consistent power delivery.
Engineered for Performance and Easy Maintenance
- Filters crankcase vapors, unburnt fuel, and moisture before re-entry to engine
- Reduces detonation and knock from contaminated intake charge
- Two-piece design unscrews for easy cleaning and service
- Internal venting keeps oil in the canister, not on your bike or ground
- Proudly made in the U.S.A.
Optimize Your Engine's Health
Installing the Moroso Air/Oil Separator is a straightforward process for most V-twin engines, plumbing inline with your existing breather system. This upgrade is ideal for riders who push their bikes hard or simply want to ensure the cleanest possible intake charge for their Milwaukee-Eight, Twin Cam, or Evolution engine. Pair it with a high-flow air cleaner for a complete intake system overhaul.
Specifications
- Brand: Moroso
- Manufacturer Part #: 85711
- UPC: 84663857119
- Length: 9 in
- Width: 6 in
- Height: 5 in
- Weight: 2 lbs
Common questions
How often should I clean the Moroso Air/Oil Separator?
We recommend checking the canister every 1,000–2,000 miles, depending on your riding style and conditions. Empty and rinse it when oil accumulates to ensure optimal performance.
Is this a universal fit for V-twin engines?
Yes, this Moroso Air/Oil Separator is designed for universal fitment on V-twin engines and plumbs inline with the breather system on most Harley-Davidson and Indian Motorcycle models. Always confirm fitment with our Shop by Bike tool before ordering.
Does this separator vent to the atmosphere?
No, this Moroso Air/Oil Separator features internal venting, which means separated oil is collected within the canister. This prevents oil from being vented onto your motorcycle or the ground.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | Moroso |
| TYPE | Intake/Carb/Fuel System |
| SKU | 82-9510 |
| WEIGHT | 2.0 lb |
