The vast majority of Max engines across all their classes are used by Club level drivers that keep the same unit for years and have it serviced annually. The market for these products remains the strongest single product that the sport of Karting has ever seen.
New parts are covered by the unique BRP-ROTAX warranty. There are however many regular maintenance tasks that can easily be completed by the owner, mechanic or friend. These are the items outside the sealed engine unit, especially the Rotax electrics which just require a little regular attention to ensure that reliability and performance remain at the top of their game.
The Battery is the heart of any electric start vehicle it should be kept clean and regularly recharged to keep it in good condition. The Battery support must also be in good condition with the foam insulation material properly in place to protect against vibration. The battery connections need to be tight to give a good supply of current. Care must be taken to ensure that the charging Jack plug cannot earth to the chassis. I see so many of these just loose and close to a metal earthing point. If the centre electrode can arc to earth it is an almost certain ignition pack replacement. A completely avoidable expense. You can bet your life it will happen within sight of the chequered flag!
The wiring loom can also do with a check over and clean. If you do this regularly and that means taking it off the chassis, you will find any chafed areas or connectors that could do with repair. Repair to the wiring harness is allowed within the regulations but not modification. This means that you may replace a damaged connector or change the spade terminals on an old style loom to the new ring type, however you must not significantly shorten the cables. If the harness is worn through you need to decide whether it can reasonably be repaired or does it really need to be replaced in order for it to remain dependable.
If the Starter Motor gives trouble I would recommend that you take it to a Service Centre or replace it. The unit is very good but once it starts to play up it can only get worse.
The Switches are very good and seldom cause a problem, it is important for them to be carefully handled and sited, the cables to them should not be under strain and always remember the two big wires go to the big button!