Odd Oil In Airbox Motorcycle Solutions?

No secret if you follow along with my adventures as a new motorcycle rider and new owner of a TaoTao TBR7 dual-sport motorcycle.

I have been fixing problems with the motorcycle for a while, and the TBR7 motorcycle is much like its Chonda – Cousins with some design and material issues. If you are an RPS Hawk 250 owner, you understand what I mean. Feel free to leave a comment below. So now let’s move on to why is there engine oil in air filter of my motorcycle?

Let’s review some of my oil in airbox motorcycle solutions I am going over.

Oil In The Airbox A Common Motorcycle Problem?

Oil in the motorcycle airbox is commonly discussed topic on many motorcycle forums, but actual oil in the motorcycle filter airbox is not a common problem. It’s only widely talked about, since it’s dreaded.

1. Worn motorcycle engine piston rings.

There is excessive exhaust gas leakage into the crankcase with worn piston rings. To prevent pressure build-up, there is a crankcase breather system. It’s usually just a tube that vents crankcase air into the airbox. If the motorcycle piston rings are worn, you might have excessive venting, carrying excessive oil into your airbox.

2. Broken breather tube component.

I found the TBR7 bike has an ‘acorn’ looking item on the breather hose filled with some open-cell foam. It seems to be an oil catch. I believe it catches oil droplets and oil vapor and allows the oil to drain back into the crankcase sump. I was overfilling(barely) my motorcycle oil sump, and I believe I was overwhelming the breather tube oil catch filter. Since then, I have been more careful about refilling the motorcycle after an oil change.

3. Poor engine design or motorcycle build.

Yes, I went there. I determined the TaoTao TBR7 motorcycle has a design/building flaw in its crankcase ventilation system. Just my opinion, but I don’t believe the breathing tube exiting the breather oil catch filter should slope downward towards the airbox. This slope prevents oil that gets past the catch system from draining back into the motorcycle oil sump.

Tried To Stop The Oil In The Motorcycle’s Airbox.

I prevent excessive wear on the engine and its piston rings with regular oil changes(TBR7 Oil Changes Steps) and with good oil (TBR7 Oil Type Do I Need?). I also ensure I don’t overfill the oil sump after an oil change. However, still getting oil in the airbox, which requires me to either drain it (Draining The Oil In TBR7 Air Filter Box) or wear it on my leg.

Oil In Airbox Motorcycle Solutions I Found.

Now I have been checking the Chonda forums for solutions. “Chonda” is slang for Chinese bikes based on Honda designs. The TaoTao TBR7 and RPS Hawk 250, like many other Chonda’s, seem to have an engine based on Honda’s CG-125/150 engine. Now that the history lesson is over, let’s move on.

After checking the Chonda Forums and pages, I found that the solutions are creative, and some are dumb. Yeah, I said it dumb, you’ll see. Here are some of the oil in airbox motorcycle solutions I found.

Proposed Oil In Airbox Motorcycle Solutions:

1. Completely remove the breathing tube.

This change allows the oil vapor to directly vent to air. Any oil carryover will be lost in the airflow or drip down the lower components of the motorcycle.

Sure this will eliminate the oil in the airbox problem, but now my motorcycle will leave an oil mess under it, and any splashing water, or dirt, has direct access into my engine’s crankcase.

Yeah, dumb but still one of oil in airbox motorcycle solutions I found posted.

2. Direct the breathing tube onto the motorcycle chain.

This modification is interesting; by doing this, you can create an automatic chain oiler. The leaking oil is reused, and the airbox stays clean.

I do not like this. The engine oil is thinner than the oil/grease/wax I use on my chain. This viscosity difference means the oil will be flung everywhere, and again I chance to wear the oil.

Not ideal, one of the more practical oil in airbox motorcycle solutions I read, but nah.

3. Capping the breather tube.

By capping the breather tube, you defeat the whole purpose of the motorcycle’s crankcase ventilation system. I believe it will over-pressurize the crankcase, affect engine output, and create leaks elsewhere on the motorcycle.

No, this can be one of the most damaging oil in airbox motorcycle solutions I read.

4. Re-slope the breather tube upward.

This one is a good idea, let me explain. Take the breather tube and have it enter the airbox near the top, under the motorcycle cycle filter, but sloped enough any oil droplets can drain back to the motorcycle engine oil sump.

I like this idea. It recovers the oil, prevents oil collection in the airbox, and keeps the breather tube high enough to prevent splashed water or dirt from getting into the engine crankcase. This solution has promise.

Note: I tried this, just a different variation, I made the crankcase breather tube very long, it’s working for now: (Oil In Motorcycle Filter Airbox, Fixed). Have to say this one of the oil in airbox motorcycle solutions I read is working, but not perfect.

5. Motorcycle Oil Catch Cans.

This is something I was unfamiliar with, but so interesting I decided to create a separate post about it. Motorcycle Oil Catch Cans, The ultimate of oil in airbox motorcycle solutions?

These are the ideas I have so far, and I will post what I went with and the outcome later. I just don’t want to start drilling holes in my motorcycle filter airbox without first deciding the best solution to go with.

If I find other airbox oil leakage solutions worth writing about, I will add them to this post. 

Motorcycle Problems and Solutions

Oil leaking into a motorcycle’s airbox is a small problem, but with these Chinese-made cheap dual-sport motorcycles, it seems very common.

If you own a motorcycle plagued with problems, have solutions you found, and would like to share them with everyone, please leave a comment.

Thanks for following along!

Ride Safe, Ride Fun!

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