Mikuni Carb Circuits

Doing my Mikuni carbs from my '83 Seca 550. Thought I'd put together some pictures.

The Idle Circuit:

 

The Emulsion Air Circuit: (I'm not sure if that's the correct name for the circuit. It's the air that 'percolates' around the Main Nozzle (aka Emulsion Tube) to help atomize the fuel in the Needle/Main circuit)

 

And the Enrichener (aka Choke) circuit:

 

The only remaining circuit is the Main. Incorporates the throttle butterfly, the diaphragm and slide piston, the main venturi, the needle jet and jet needle and the main jet.

But I haven't doctored up those photos yet.

Hopefully, this helps to visualize why carb cleaning is so important and why you can't cut corners on cleaning and what all needs to be cleaned.

And, it helps to show what's going on when you're syncing the four carbs, when you're pushing the choke lever, when you're tweaking the idle mixture screws, and when you're twisting the throttle, etc.

 

A true masterpiece.

What I should do, if you have no objections, is to combine these pictures with some Chacal sent me where someone cut a Mikuni carb body apart, revealing the passages inside the body.

Now, if someone could autopsy a Hitachi carb body to show the internal passages, that would be grrreeeeeeeeaaaat...

 

Any other requests?

 

No worries - of course you can. Send me an email address, and I can send you the original photos - marked up and NOT marked up, if you want 'em.

 

Make sure the cuts are from multiple angles. The passages don't just go from front to back, ya know. :mrgreen:

PM heading your way shortly.