6 turns out on Mixture Screw! What?

[quiktaco]

Okay, so I just replaced the plugs on my 96.  They previously were black (I think because it was ridden with the choke on by the PO), but they carbon was burnt off after a bit, and now they are white, so the bike is running lean, obviously.  I'm pretty sure the jets haven't been touched, but the mixture screws have.  The brass caps are out already, and I turned them in to see what they were set at.  6 TURNS OUT!  I didn't know that they could go that far out.  They actually went 8 turns out without falling out, so I left them at 6 (and yes this is full turns, not half turns).

So I guess my question is, what would be wrong that they'd need to be 6 turns out?  I'm planning on rejetting it soon, just waiting for the pilots to come in at Suzuki.  Also, I'm sure there is a point in the turns out that it no longer would have an affect more than the max.  Does anyone know what that is?

[coll0412]

IT makes it really rich. Try 2.5 turns out and see how she runs, otherwise they might have been compensating for a vacuum leak.

[quiktaco]

That's a possibility.  How is it that you check for a vaccuum leak?  I heard you can use WD-40, and spray it around the boots and what not.  Is that right?

[coll0412]

Yeah, it will rev up as the WD-40 gets sucked in. I would just try adjusting them back to like 3 turns out and see what happens, they also vibrate loose sometimes if the spring inside of them has gotten weak.