Lifting weights will help you fight arm pump. It is important that you construct an exercise program that translates to what you are conditioning yourself for. With this in mind you want to condition your muscles for maximum endurance.
Do exercises that involve low weight with high repetitions (12 to 15 reps) for a minimum of 3 sets each exercise, but no more than 15 total sets for a particular muscle group. Suggested exercises for your biceps would include straight-bar curls, dumbbell curls and, most importantly for arm pump, reverse curls. For Triceps I would suggest tricep extensions (on a bench or at a cable machine), reverse extensions and (once again for arm pump) close-grip benching.
Of course a balance of all muscles is most important so do include exercises for your shoulders, back, chest, abdominals and legs as well. This, combined with some cardio work will give you the strength and endurance to fight-off arm pump. BTW, for cardio I think that running, spin cycling and a stairmaster translate best to a dirtbike environment.
An added benefit to all of the above is that you’ll look and feel great.
Gary