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Help diagnose loss of power on 2005 Rotax 4Tec Supercharged

Markk

Jetboaters Lieutenant
Messages
280
Reaction score
325
Points
167
Location
Grand Prairie 75054
Boat Make
Yamaha
Year
2014
Boat Model
Limited S
Boat Length
24
Has fast key installed. Plugs were changed last season. No water in hull. Impeller looks smooth. Fresh fuel in tank. Plug tips look clean(bright and white). Unit has 120hrs on it.

Engine will not make full power. After on plane will rev to 7200rpm but arrives slowly. Out of water owner tested quickly rev to 8200 and sounds like supercharger is kicking in.

Please give ideas where to look for lost power.
 

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Where is air filter? Buried in front locker
 
Bump. I know not a yammie..... any ideas?
 
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