not starting

[ds450xracer]

you need to slide feeler gauges between the cam and the valve buckets to see what ur clearances are now, then put in smaller or larger shims till you get to where you need to be, there is no magic number anyone will be able to tell you. It would probably be alot easier on your part to order a full shim kit because i dont believe the shims that come in the bike are marked with what size they are, so it'll make it difficult to determine what size you need to replace them with.