Mikuni carb tuning guide

[rastus]

This was sent to me by a mate of mine who is a great motorcycle tuner. Enjoy.......go to site and read.

Mikuni carburetor operation and tuning

 

[1fifty1wheel]

I do like it but.....

"If the screw is located near the back, it regulates how much air enters the circuit. If the screw is turned in, it reduces the amount of air and richens the mixture. If it is turned out, it opens the passage more and allows more air into the circuit which results in a lean mixture. If the screw is located near the front, it regulated fuel. The mixture will be leaner if it is screwed in and richer if screwed out. If the air screw has to be turned more than 2 turns out for best idling, the next smaller size pilot jet will be needed. "

May cause confusion, the end part relating to installing a smaller pilot jet refers to the first idle screw type. It does say 'Air screw' but at first glance i missed this and thought WRONG.

Also a proof read may be of benefit?

 

[rastus]

Hey mate I just copied and pasted the addy here my mate got from somewhere. I didn't write it nor did he. Not my fault. Not guilty bloke. I thought it a bit weird when I read it too........

 

[Cactus Jack]

The air filter side of a carb is the "Mouth" or "Front" of a carb ... a screw that's on the "Mouth" aka intake side of a carb is an AIR screw ... turning it in richens the pilot mixture and turning it out leans it ...

The manifold mount side is the "Butt" aka the outlet or rear end of the carb ... a screw that's on the "Butt" side of a carb is a FUEL screw ... turning it out richens the mixture and turning it in leans it ...

You measure the size of a carb on the "Mouth side , just before the slide (height + width divided by two) ... NOT the manifold mount end ... aka the Butt hole side ...

 

[1fifty1wheel]

Rastus,
Yeah mate, wasn't having a dig at you personally just pointing out it needs to be read carefully and interpreted correctly.

The way Cactus has put it is much better (as usual) using the correct terms.
Reffering to "front and back" also may cause confusion. It depends on how you look at the carb, if looking whilst installed font is the butt, if looking down the mouth one would assume it to be the front and the back to be the butt.