Quote Originally Posted by axa View Post
has anyone toyed with this adjustment much, isn't this an air/fuel mixture?
exactly how does it work/how should it be used.
Go to http://wem.walbro.com/distributors/s...CAEBURETOR.pdf
and read the section about "Idle and Low Speed". Our PZ30 carburetor is similar to the PZ26.
"Open the screw will allow more fuel to enter the engine..."

A good chart to study to see what tuning affects what is
Carbtuningchart.jpg

Our needle does not have the clip position so I raised the needle by putting two M3 washers under the needle head.

I am now at 108 main jet , 42 slow jet, and two M3 washers under the needle and with the 30 tooth rear I have run 65 MPH indicated.

Not saying that my combination is optimal but I'm leaving it set that way for a while as it seems to be running pretty good.