MSR stove tips
I have used several versions, going back 25 years. Own 3, all of them old models XGK and Whisperlite,and have used them over 1000 days. Here is what I eventually learned. O rings are the thing to carry, either one of the spares kits they sell, or just go to any auto parts place and choose o rings out of the bin. The one that wears out first is the one where the tube connects to the bottle. Keeping it lubed helps it last longer-nose grease works fine.The next thing is one of the little rubber balls, if the stove uses a check valve,(those thigs bounce and disappear) and then a spare jet or two. Carb cleaner in the gas keeps things from varnishing over time. The pump cup needs to be kept lubed, and a spare or two carried. It is possible to cut one out of leather if you don't have a spare. Any kind will do- I have used moose hide, the all purpose Canadian bodge choice, and inner tube before I learned to carry spares, and replace suspicious rubber parts before each trip.
Using clean fuel helps a lot,or a least filtering it before you use it.Coffee filter paper works, just don't use it for food after. Keeping the pump in the bottle between burns is fine, but release the pressure first.Clean and lubed is the best preventative