evinrude 120hp v4 loss of speed

[alain]

i have a loss of speed (use to go 50moph and now around 40mph what can i do to tune it ?(i change the spark plug cleaned the card even upgrade the gas octane to 98)

 

[Dhadley]

Re: evinrude 120hp v4 loss of speed

Did you make these changes before or after your performance loss? What RPM did you turn vs what you can turn now?<br /><br />What plugs? If you went to a hotter plug along with a hotter fuel, that may not be a good thing. What octane is recommended in Canada for the OMC's?<br /><br />Good luck!