2005 Ski-Doo Racing Handbook, Page 362Get this manual
SECTION 082005 MX 550 AND 380 FC
GENERAL
CAUTION: While performing any engine related procedure, always make sure that the working area is clean and free from dust or particles to reduce the risk of damaging the engine
TROUBLESHOOTING
Before completely disassemble engine, check airtightnessRefer to LEAK TEST AND ENGINE DIMENSION MEASUREMENTNOTE: The following procedures can be done without removing the engine from chassis
CLEANING
Discard all gasketsUse Gasket Remover (PN 413 708 500) to clean mating surfacesClean all metal components in non-ferrous metal cleanerScrape off carbon formation from cylinder exhaust port, cylinder head and piston dome using wooden spatulaNOTE: The letters AUS and arrow on the piston dome must be visible after cleaningClean the piston ring grooves with groove cleaner tool, or with piece of broken ring