For those of you who, just like me, do not immediately understand the air system:

This is the diagram found on the air box.

The air system consists of these main parts:
- two air solenoids
These are commanded by the PGM IV to either open or close. I haven't been able to find out whether they are commanded to open at the same time or whether the PGM IV unit first opens one and if more air is needed, then the second one. They are not parallel wired so I assume they are controlled separately.

- Sub-air filter
The air to the carburetor main emulsion tube is drawn through this little filter sitting in the r/h underside of the airbox. It is two stage, one coarse and a fine paper filter.

- Loads of tubing and some connector

Note that the 4-way connector has a "dead end" with a plug. This plug does not seem to have a function except one could measure the vacuum at various operating conditions if a vacuum meter was attached instead of the plug.

This is how it works:
(1) If the air solenoids are not commanded by the PGM IV to open, the carburetors draw the air to the main jet emulsion tube through the 4 way connector directly from the sub air filter. There is a < 1 mm brass jet in the passage to the sub air filter in the 4-way connector whichprecisely limits the air drawn this way.



(2) If one or both air solenoids are commanded to open (by powering them with 12V), additional air flows through the solenoids to the carburetors.

Heya Gepe

Thanks for the post, i'm interested in learning more about the carb air system.

I've read the post and looked at the diagrams, but i don't understand what the purpose of the system is.

It almost looks like it's a controlled vent or breather of the air in the float bowls?

Maybe someone could explain it's purpose.

Cheers

Robert

Here is an extract from the manual explaining the purpose of the air correction system

So to answer your question in 25 words of less:

The air solenoid system is used to control the amount of air for the air/fuel mixture based on the conditions coming from other data points on the bike through the PGM unit.

Heya

Thanks very much Moa and cgallant.
I wonder if they would use a lambda sensor to control it if it was designed today?

cheers

very unlikely because when used on a two stroke, a lambda sensor has a very limited life due to the oil in the exhaust damaging the Nerst cell.

That's a hostile environment to live in,so wear should be expected.

This scheme was a economic solution to Fuel injection!

Tested on NSR 250 cadalora bat not functional and reliable ..


See Bimota 500V
_________________
Alessandro Cucco
via Brigate Partigiane 43c
54033 Carrara (MS) Italy

"Tested on NSR 250 cadalora ..."

What is "NSR250 cadalora"? Why not functional and reliable? The air correction system on my bike worked flawlessly for 46.000 km, I wouldn't call the unreliable...

No wonder the fuel injection on the Bimota did not work, this small company probably did not have the money and engineers to develop something as new as this.

I was referring to the injection! (tested by Kanemoto) Honda HRC
_________________
Alessandro Cucco
via Brigate Partigiane 43c
54033 Carrara (MS) Italy