Loss of power over time

ruggerole

Loss of power over time.

2001 232CC with 5.7 EFI with Bravo3 26 pitch. Last year I was able to get 50 mph and 4800 RPM. This year 43 MPH and 4300 RPM. Changed rotor, cap, wires, plugs, fuel filter and water separator. What should I look at next?

PickleRick

Any damage to props or growth on hull? 

ruggerole

No damage to props, no growth. No bottom paint. Trailer the boat and the hull is in great shape.

aero3113

Possibly dirty injectors if everything else checks out good.

raybo3

Compression check on all cylinders????????

212rowboat

raybo3 said:

Compression check on all cylinders????????

check for air obstruction- swap or clean your air filters.  
check the belts and what they operate- they may be stealing power if a bearing is tight or a accessory is not turning freely (parasitic loss at the crank which drives that belt)... it doesn't take much to sap power when the sap is on the crank (you can dang near stop an idling engine with your hand by slowing the crank, but i wouldn't recommend trying it lol)... 
check fuel pressure- your pump may be starting to get tired.. 
check slop in your throttle cable- you may simply not be reaching WOT the engine is capable of.. 
check the trim limit.. you should be able to trim up until it starts to porpoise (bow goes up and down) and pull back just a touch to stop that bounce--- i.e. proper trim.
and if all that checks out? go with @raybo3 's check next... 

PickleRick

Did you service the engine to fix the low power issue?   If it didn't start til after check firing order and plugs/wires for spark/gap