Make a Decompression one way valve In less than 500 yen



Custom, such as to control the crankcase pressure in a one-way valve is became popular for a period of time.

At the time, I am also wanted, but Those that are commercially available are expensive.

Searching a cheaper way Internet by such reasons,I made by myself.

By the way, There was change in the engine behavior by mounting of the internal pressure control one-way valve.

However, it did not know is good or bad judgment,

After all, the one-way valve was removal immediately …

Parts are sold in water pipe corner of the DIY shop.


Parts price is about 500 yen.

Things you need to get prepared this, and the tee of golf, is the connection parts of the water pipe.

Single item price is less than or equal to 100 yen. Let appropriately buy.


Create a one-way valve in such parts.

By the way, If you use a water pipe connection parts as breather hose connection will atmosphere such as steam punk. I love steam punk.

process the golf tee

Images are processed in such a form with a metal Bar file tool.

When it’s overdone, it won’t be in one way.


Dig a trench in the places 2-4 in the vertical , This groove will be the internal pressure discharge groove.

Is the most efficient is three places of the grooves in the results that I have tried.

Adjust in-kind

Put the golf tee on the water pipe components to be the body of the one-way valve.


Make sure the movement of the one-way valve, The one-way valve there is a way to try in addition to the mouth.

It reworked the case where the operation of a golf tee or there is a gap is bad.


It is completed in such a form.

Connection location of the one-way valve will be in the hole to the internal crankcase.

Simple place, change the spout of engine oil to the type of breather hose can be connected. and Connected to there …

But, I do not recommend here.

While it referred to as, This place is the place where a change is felt most….


If you make a connection as usual, Connection to the blow-by gas hose is desirable.


Red circle portion of the image will be the outlet of the blow-by gas.

This breather hose is connected to the AIS, it will lead to the air cleaner BOX.

Operating sound is clattering.

Rattling and golf tee you will hear the sound of up and down movement in the engine start-up.

If this operation sound you hear, the one-way valve is operating normally.

And the one-way valve brings a change in the ride.

However, I do not know well be bad whether it is good for the engine, In addition, there was no atmosphere to become faster because wearing a one-way valve.

When it’s possibly precise and is an expensive one-way valve, you may be able to get the effect more.

Because I am a poor man, I do not buy such a expensive goods.

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