Low power at WOT BF135

[Pewpew211]

my neighbor has an (assumed) 2009MY bf 135 that has trouble with power at WOT. I've changed the spark plugs as this is a recent acquisition for him and he didn't know hen they were last done.

It will run fine at idle, but when he opens it up the boat will just pitch up and just sit there. The engine seems to rev up but not really going anywhere. Could this be a fuel filter issue?

 

[jgmo]

Hi,

Based on what you're saying, my first "suspicion" is that he may have a bad propeller hub. You can check it by.match marking the inner and outer propeller sections with a felt tip pen.

By aeither putting the transmission in gear with the engine OFF and then trying to turn the prop by hand OR, better, taking the boat out for a short run and then checking to see if the marks you made are misaligned.

If the matks misalign, the hub is bad and considered "spun". It will need to be repaired or replaced.

Note: when shifting an outboard with the engine off, always have someone slowly rotate the prop (direction doesn't matter) as you move the shift lever. That keeps the clutch inside the transmission from accidentally binding up.

Good luck.