Custom intake manifold.

[kiwibaotianist]

After fiting a free-flow filter to my bike, I discovered I had nowhere to put the camshaft/crankcase breather, I decided to make a custom manifold for my scoot.

This is what I came up with:

The manifold with barbs for the breather hoses:


The manifold in the bike where it belongs:


Filter position:



The entire thing is comprised of 1 1/2" PVC drain pipe, two 6mm elbow joints and a 90* bend and a 2" length of radiator hose.

This seems to make the bike a little more responsive than just slaping a free-flow filter on the carb outlet, the bike revs better and it is noticibly quieter. You also get the nice shiny thing to look at

[enu06]

Very innovative, have your first karma!

[Scootin]

I agree. Very clever design

[Macrofeet]

no offence is intended with this post
mod looks great

Just wonderd have you tested in rain yet ?

[kiwibaotianist]

I have not yet tested the bike in the rain, it's currently spring where I live.

Although the photo does not show it, the filter actualy sits just underneath the left hand side fairing. The issue of spray from the back tyre is going to be solved with a custom mudgaurd in the very near future.

[krajes]

look fine but should the crankcase breather be before air filter

[Macrofeet]

ahh that explains it , it looks like its sticking out in the pic so that much run off from the plasic would be going directly into filter

[krajes]

but is it safe to have breather conected straight to carb? I dont think that air from breather is 100% clean

[kiwibaotianist]

Good point, I will probably stick a paper element fuel filter between the breather and the manifold to absorb most of the vaporisied oil.

[blubayou]

So long as your engine is in good condition, dumping the breather direct into the inlet will do no harm, tho' a flame trap (gauze) may be a good Idea. Mine vents to atmosphere.

Have a karma for innovation.

[hypojam]

Nice

[krajes]

is it very important to have breather connected to carb?

[krajes]

why?

[blubayou]

It's not at all important to have the breather connected to the carb performance wise, in fact I seem to remember that oil vapour lowers the octane rating of the mixture, only really a consideration if you have a knackered smokey motor.

The reason for burning off the breather vapour is purely environmental.

[krajes]

asking only because I Head problem with my breather, when whose connected to air box its slow me down, after disconnecting my breather everything is OK . Still don't now the reason for this