I would appreciate if some of you could clear up a few queries for me. I read various discussions on how to enhance the restricted bikes from their stock form, as the WR is absolutely flat compared to my ex YZ426. The quick win I understand is the a YZ throttle stop (5JG-14591-00-00) as well as the exhaust insert (GYT-5TJ93-75-00) which also keeps the noise level within 96dbs Q1: Can any one tell me if I need to change the jetting if I remove the existing exhaust insert? Q2: While I wait for the part to arrive, If I remove what looks like the washer on the external end the existing exhaust insert but retain the spark arrestor, will this increase the noise level? I need to keep the noise down as I intend to compete in the local Hare and Hounds and they are not too friendly with loud bikes. Q3: I have read a lot about the Woodruff Key, has this problem being eliminated with the 2004 models?