Check your owners manual for recommended service intervals to be performed.

The Magnum owners manual recommends that you adjust the valves at 1000 hrs. and check injectors at 2000 hrs.  This is one area that is very frequently overlooked.  Other important time intervals from the Magnum manual are:
        Engine oil & filters (we recommend 100 hrs.)                            250 hrs.
        Fuel filters - primary, secondary and in line                                500 hrs.
        Coolant & conditioner                                                                 2000 hrs.
        Coolant filter                                                                                   500 hrs.
        Transmission/hydraulic oil                                                          1500 hrs.
        Front differentials & planetaries (first change at 50 hrs.)        1000 hrs.
        Air filters                                                                                       1000 hrs.

We perform "The Top End Tune-up"  which consists of :
        Adjustment of intake and exhaust valves.
        Check injection pump timing.
        Remove & test injectors.
        Replace - injector seals, valve cover gasket, injector sleeves and o-rings & washers.
        (Injectors and other parts are extra.)