Some common Sea-Doo repairs include variable trim system failure and supercharger failure. Faulty rectifiers on the vehicles can cause voltage problems, and engines rebuilt with inferior parts may experience failure more quickly. Trim system failure is primarily caused by moisture entering the motor, relay or VTS housing unit. Water inside these parts can corrode vital parts of the engine; rust or a white, chalky residue are signs of corrosion.
Signs of VTS failure include a non-responsive VTS indicator on the vehicle's dashboard and lack of movement in the Sea-Doo nozzle. If the motor is corroded, it can result in blown fuses that cause these problems. New fuses can restore relay from the motor to the battery; properly-working spark plugs turn medium-tan to dark tan in color. If the motor operates when directly connected to the battery, a faulty switch or relay could be the issue. Damage to the relay is more common on older Sea-Doo models, particularly those manufactured before 2003.
Counterbalance gear failures are common Sea-Doo repairs for the 787 and 947 models and are often caused when an operator neglects to check the machine's oil reservoirs. According to Sea-Doo, the counterbalance reservoir should be checked after every 50 hours of use to help prevent this problem. Owners of Supercharged Sea-Doos manufactured before 2007 commonly experience engine failure due to faulty ceramic washers that shatter when the engine operates at high speeds. Users can refit the supercharger unit with metal washers to prevent this from happening. Sea-Doo recommends ensuring engines are correctly timed for peak performance and suggests that owners rinse salt water from engines after each use to prevent corrosion.