franch, what year is your bike? The fiche Savage_Rob shows is from a late model and not the old 80s bikes.
When you get it out, check which tip it has on it. I ordered one from Ron Ayers for my 87 model, and they sent me a different one than what came out of it.
Luckily I hadn't messed my screw up that bad, and was able to flatten the top with the side of the cutting wheel in my die grinder, then use the edge of the wheel to cut a new slot. Works great, but you have to clean up any roughness on the threads and be careful not to gall the threads as you ease the "new" screw back in.
WARNING: In case any bystander attempt to follow my example: Working with bare fingers close to a CUTTING wheel that is spinning at thousands of RPMs is not something I advise for anyone thin skinned, or in the habit of saying "Whoops" when handling tiny parts. Even leather gloves will only provide a minimum of protection from a wheel that is designed to cut metal.
The one on top in the picture below is the old one before I "repaired" it...
The one on bottom is what Ron Ayers sent me as their part # 13279-47070 Which shows as item #47 (screwpilot) on the carb fiche for an 87 model LS-650F(H):
http://www.ronayers.com/fiche/300_0039/carburetor/carburetor.cfm?man=su&group...BTW, my repaired one works fine, even though there is no top on it, the slot is actually in the threaded part.
Hope you get the right one, and it goes in easy!