pilot mixture screw

I have a 82 650 Seca (Canadian) with Hitachi carbs and I'm a little confused what the "rule of thumb is" for setting the mixture screw is. Looked into the Church of Clean and not sure if it's 1 1/2 turns out or 3 -3 1/2 turns out. The caps were off on no. 1 and 4 cyl., but the 2 and 3 still had some type of rubber insert or cap. I dug out the caps They basically turned to powder as I dug them out. So for all 4 screws I turned them in till they seated. Counting the turns were cyl 1 3 1/4 turns in, cyl 2 1 1/2 turns, cyl3 1 1/2 turns and 4 cyl 3 1/2 turns in. So if those were factory caps, is my assumption is for these carbs it's 1 1/2 turns out?
Thanks,

 

Factory settings may have been that way. They were set for emissions reasons, not necessarily performance.

It is advised that you set them all at 2.5 turns out as a 'starting point' prior to synching and color tuning.

 

Stumpy is correct

 

It's 1-1/2 (or so) for the carbs with the coarse-threaded mixture screws (1980-81, maybe some 1982 XJ650 models). All other Hitachi/Mikuni carbs use ultra-fine-threaded mixture screws, and they use the 3-1/2 turns figure. BTW, 2 turns on the coarse thread screw is about the same lift (screw movement thru the threads) as 3-1/2 on the fine threaded screws.

 

Thanks for your replies.I believe the threads are coarse on mine. So I'll try 1 1/2 to start with. The mixture seemed to be rich when I pulled the plugs. Once it warms up here enough to put the carbs back on, then when it start,s I'll vacuum sync and try that new colortune.