85hp Evinrude sudden increase in RPM

[ajax3809]

I have an old 85hp Evinrude that will suddenly jump up about 300-400rpm when cruising. I have to pull back on the throttle to keep it taking off. Any idea what would cause this? Idle is fine and just recently replaced some ignition coils

 

[faztbullet]

At what RPM are you cruising???

 

[racerone]

Use a timing light one cylinderat a time.---See if you can find a cylinder with spark that suddenly comes in.------Post compresson test numbers here.

 

[fdrgator]

What you describe is somewhat normal, moreso on some boats than others. This happens when attempting to cruise at the critical speed when the boat is starting to level off into a plane.