1977 Suzuki GS750 carb adjusting and baseline settings

[holyford86]

Picked up one of these bikes for free a while back, has good compression and spark, rest of bike was junk so i pulled the motor out and held on to it. just recently installed it in an atv (there's something wrong with my head I think).

Carbs were all messed up from the previous owner using silicone to put the float bowls back on and they leaked gas very badly from worn needle/seat. Cleaned and rebuilt the carbs and reset both adjustment screws to where they were before, I think that they were set a bit out of adjustment though because the bike runs stupid rich but runs and idles screw on the bottom of the carb was set at 3 turns out and screw on the top was set to 1&3/4 turns out. I have a factory manual for the bike but it doesn't tell me how to adjust the bottom screw, just says don't mess with it in the manual. Anyone know where this should be set at baseline and where in the rpm range this thing comes into play so I can adjust it properly? I haven't messed with the synchronization of the carbs and they seem ok in that respect as there was still torque seal on the adjustment nut for the sliders.

 

[dhinch279]

Probably suppose to be about 2 turns out, but each bike can be different, it depends if they have jet kits or 4 to 1 exhaust, etc.
What I do is set the screw to 1 or 1 1/2 turns out (you don't want it to be too lean) and ride the bike around the block
Then turn it a 1/2 turn out each time until it runs well and isn't too rich.

You can also work the other way, start out rich and work your way in until you feel it's right