Hello guys,
I make service on my gs500 2002 32.1kW and found white spark plugs like these : http://s134.photobucket.com/user/pimpin88_photos/media/Saturn%20white%20spark%20plugs/P7150028.jpg.html

I search what that mean and found, that I have lean mixture ( next symptom have smaller power and hard starting )
So what can I do to fix that problem ? I looked in haynes but nothing.

You're best just to re-jet your bike. I assume its probably on stock jetting.

02 bike ? Stock airbox and pipe ??
20 pilots and 132.5 mains 3 turns and 1 washer.

Cool.
Buddha.

Thank you for your answers.

Yeas I have everything stock.
I checked my carb and found I.D number  : 01DE L191 -  still " 20 pilots and 132.5 mains 3 turns and 1 washer" ?