Strange findings on mixture screw

[jdoorn14]

I've been in the process of doing a thorough cleaning of my carbs due to some poor performance around/just off idle and I'm getting close to putting things back on the bike. I replaced the pilot and main jets with +1 while I was in there from stock to 20/60/132.5. Exhaust and air filter are stock, so I was just going to verify the position of each mixture screw. The left carb was the normal ~2.5 turns out. However, as I began tightening the right mixture screw to check stock setting, I was shocked to find it was tightened all the way in. Now, I had to drill out the caps, so I have to believe this was set from the factory. I'm the second owner. The first owner only did basic maintenance himself and took to dealer for other service. Has anyone else heard of this?

It does start to explain why the right spark plug always looked extra lean as compared to the left. I just thought it was odd, so I thought I'd share.

[Suzuki Stevo]

I had to drill out the caps

Drills go clockwise, turning in the idle screw is clockwise, if you so much as touched the idle screw with the drill while removing the caps, you probably ran it in, check the screw for drill to screw contact   

[jdoorn14]

I had to drill out the caps

Drills go clockwise, turning in the idle screw is clockwise, if you so much as touched the idle screw with the drill while removing the caps, you probably ran it in, check the screw for drill to screw contact   

Hmm. Now that you mention it, there was some scuffing on the screw head. It just seems like this screw takes a bit more effort than a momentary touch by a moving bit,  but maybe it only takes the lightest of touches with the rotating bit.

[Suzuki Stevo]

Lemme tell you how I know about this phenomenon 

[lucas]

Better to just spin the mixture screw than to chew up the threads which instantly ruins the carb.   I wouldn't know anything about that though.   

[jdoorn14]

Well, maybe it was just the brief touch of the rotating drill bit to the screw. That screw must turn quicker and more easily than I thought. Oh well, it's backed out to an appropriate number of turns now and with a fresh o-ring. We'll see how much trouble I caused later. Gotta get the carbs back on, sync them up, and see if things seem better or worse than before.