Oil In Motorcycle Filter Air Box, Fixed!

This problem oil in my motorcycle air box has been going on for a while. Glad I finally put together a fix for the oil leak.

I finally fixed my Air Box and no more oil is getting inside of it again!

This modification is where it ends! I have been having months of problems with oil getting into my motorcycle’s filter air box. I traced the source to the crankcase ventilation system, specifically to a section of breather hose that slopes toward the air box.

You can read my past antics with this oil and air box problem here:

Well, no more. I looked at suggestions from other Chonda owners (RPS Hawk 250, Bashon Brozz 250, and of course, my fellow TaoTao TBR7 Owners). The solution I came up with was to remove the breather hose from the air box and move it to a high point with it sloping back to the crankcase.

How Does This Fix The Oil In The Filter Air Box?

  1. This modification removes the breather hose entirely from the air box. An easy solution.

Better Than The Other Oil In The Air Box Solutions?

  1. This breather hose redirection doesn’t pollute. The oil isn’t run to the chain or the ground.
  2. The transformation recovers oil by allowing it to drain back into the crankcase sump.
  3. This improvement continues to protect the crankcase from dirt and water.
  4. No need to drain like an Motorcycle Oil Catch Can.

Ready for it? Here it is!!!! This fix is so easy!!!

Steps I Took To Create The Air Box Fix:

1.- Remove the rear body panels and seat.

2.- Removed the crankcase ventilation breather tube and oil catch.

Crank case vent system removed.
Crankcase Ventilation System, breather hose with oil catch(Acorn-looking thing with numbers).

3.- Since the original house out of the oil catch(acorn-looking thingie) doesn’t reach the point where I want to go with the breather hose, I took the oil catch to the auto store.

TBR7 oil separator removed.
Took oil catch to auto parts store for new hose and hose clamps.

4.- Get a longer hose from the auto parts store to become the new breather hose.

5.- Get hose clamps.

6.- Reinstall oil catch, with its stubby hose to the crankcase.

TBR7 oil separator installed.
Oil catch reinstalled with original clamps and stubby hose section.

7.- Route new hose from the destination(open end will be under the seat) back to oil catch; remember to put on a hose clamp.

Hose and hose clamp for new TBR7 crank case vent.
Don’t forget to add the hose clamp to the new crank case breather hose.

8.- Clamp new, longer hose to oil catch. Ensure the clamp is tight enough to prevent oil leakage.

New crank case vent hose on original TBR7 oil separator.
new crank case vent hose connected to original TBR7 crank case oil separator.

9.- Add filter to end. I didn’t buy a new crankcase filter, so I created one from a shop rag and wire ties.

Red shop rag.
Cut piece of shop rag.
red shop rag with wire tie.
Makeshift filter on the end of the crank case vent breather hose.

10.- Secure new breather hose; I used wire tires.

New improvised crank case vent filter.
New improvised crank case vent filter open end of breather hose under seat.
New crank case vent sloped upwards.
New crank case vent hose routed and sloped toward the engine crankcase.

11.- Reinstall the motorcycle seat and side panels.

12.- Test out your work, go for a ride!!! Enjoy your hard work.

I plan on updating you as to how well my fix works. If any oil makes it up that far in the breather hose with the rag on end, the rag will be discolored as an indication.  

Wow, No More Oil In My Motorcycle’s Filter Air Box. Now, what will I do with all this empty space in the air box? You’ll see, the crankcase breather hose re-route took so little time I had time to do another modification to my TBR7. I will be posting this soon. Stay Tuned!

Ride Safe, Ride Fun!

Click To See My Recommended
TBR7 Upgrades

Picture of me, as a New Motorcyclist.
Just Me…Newly Licensed.

Hi I’m Tom, A New Motorcycle Rider and Blog Author.

I am a new rider(Pa Learners Permit at the end of 2020, and I received a Pa Motorcycle License in 2021 after passing a Motorcycle Safety Course).

I bought my first motorcycle, a TaoTao TBR7, at the beginning of 2021 and have been doing upgrades on that motorcycle since.

I added to my motorcycle collection by buying a Boom Vader Gen 2 in 2022, and that Grom-Clone motorcycle has been upgraded by me as well.

I continue to ride my Boom Vader Gen 2 motorcycle as well as my TaoTao TBR7 dual-sport bike.

Read more on my About Me page.

Fun Fact: I’ve only been on one group ride.

3 thoughts on “Oil In Motorcycle Filter Air Box, Fixed!”

    • Good question, I had to recheck the photos.

      I took the oil separator to the auto place, to size it up. But, to get the right size faster my hose reads it’s a heater hose 1/2″ in diameter. I suspect that’s the internal diameter.

      Hope this helps.


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