The effect of the inner diameter expansion Intake manifold

Intake system

Change a carburetor and a throttle body for a large diameter and may aim at the power-up.

But an effect is insufficient when the aeration mouth of the inside diameter and the cylinder head of the intake manifold does not spread on this occasion.


In addition, let’s confirm the inside diameter of the intake manifold to know one’s motorcycle because there is the motorcycle model that a maker coordinates intake manifold for power regulation.

Expansion of aeration mouth is here


This will be the image of the inner diameter expanding processing of the intake manifold.


Also together and inner diameter expanding Bakelite. Just a little may be tapered if possible.

Although processing of the intake manifold is cutting with an electric drill,

Finish is better to finish in slippery to eliminate the uneven.

By the way, if the processing of Bakelite manifold cylinder head air inlet

The durability and stability change than normal and may breathe in the second air.


In such a case let’s use a liquid gasket.

How to check the Secondary air from gap, See here