Exhaust Port Crush Gasket.  When these wear out, you get rattles and leaks in your exhaust system. Replacing them and tightening down all your exhaust hardware will make for a much quieter motorcycle.  These are new, made by K&L Supply and replace OEM part number 11009-1906

Price $20 per set of 4

‚ÄčEngine Gaskets and Seals

KZ1000P.com