my 2006 sportsmna 800 developed a rattling noise somewhere around my right leg. i have checked the exhaust shieds and they all seem tight. i have also checked to see if the exhaust is cracked where the 2 come together. i notice it more when the back wheels are turning. when in park it does it a little but is more noticable when in gear. rattles when it is both hot and cold. anything else i could check? it seems to start around 3200 rpms.