Air mixture adjustment recommendations for bone stock '83 xs650

[watson]

Hi all,
I'm sure this has been covered before but I'm looking for a good starting point for my air mixture screws. I have a stock '83 xs650 with Mikuni bs34s, stock jets, stock air boxes and stock exhaust. I think I remember reading that 3 turns out from seated was appropriate for this bike, but any advice is greatly appreciated. Thank you in advance for your response and thank you Hopper for the much needed replacement carbs.

-watson

 

[weekendrider]

Yes 3 is a good starting point.

 

[I am Carbon]

i would start at 3 turns out too BS34, all: 3 turns
Warm the engine to operating temperature, then raise the idle to around 1500 rpm. On
bikes with breaker point ignitions, pull off a sparkplug cap. Electronic ignitions can be
damaged by operation with an ungrounded ignition wire. To prevent that, shut down the
engine, attach a spare sparkplug to a cap, ground the plug solidly on the engine, and
restart. Adjust the throttle stop to hold lowest steady idle, then move the fuel screw 1/4
turn each way, seeking highest idle. When you find the direction of improvement, set the
screw 1/8 turn in that direction from your starting point and again move it 1/4 turn each
way. As idle rises, lower it with the throttle stop, as changes are easiest to detect at lo.
engine speeds. Set the screw at the inmost (leanest) position that yields highest idle
speed. (And yes, I know; some owners advocate finding the point where idle drops due
to leanness, then the point where it drops due to richness, and setting the screw at the
center point. I do not concur.) Repeat for the other cylinder .this came from the carb guide

 

[XSLeo]

www.amckayltd.com/carbguide.pdf