Hello,

I am getting ready to install a set of SU's on my car.  All the stuff I read about making adjustments by turning X-Number of "Flats" has me asking this.  I don't have an adjustment knob with "Flats", I have a knurled adjustment knob with a little bump on it which I believe is to help identify the number of turns you've made.

I have no problem turning it and counting etc, but I would like to know why mine is like this.

It is on a set of 4 screws. I searched with terms like "SU" + "Flats", if anyone can point me to a thread I will happily read it, I couldn't bring it up.

Thank you,

-Brian

You've got the earlier SUs.  Click on "Spotters Guide, Z Cars" on the left side column. http://www.ztherapy.com/

I wish mine had the knobs.  

 I believe the term flats, when referring to carb adjustment refers to the old style mixture adjusters. All the (Hitachi) SUs I've seen have a knurled nut with two raised dots. One being larger than the other. Three flats would be a half turn, six flats would be a full turn just like a bolt.

Edited June 9, 20168 yr by Mark Maras

Great thank you for your help.  After I posted this I was on a rebuilding site looking for linkages to replace my jacked up choke mechanism...and saw a pic of the 70-71 set, with a clear shot of knurled knobs.

Thanks again.