Motor Problem
 

I am running a Suzuki DF175 with a Mercury Bravo I prop. Saturday when we decided to head back in we ran into some mud trying to get on plane. After that the motor started turning high RPM with loss of speed. Basically if I normally run at 5000 RPM I would be running about 40 MPH(GPS). Now at 5000 RPM I am running about 30 MPH(GPS). Also normally to get WOT (6100 RPM) I would have to trim the motor up with the throttle wide open. Well now without the motor trimmed up and with the throttle at about 3/4 I was hitting 6200 RPM. The prop doesnt not look to have been damaged. I took the prop off and pulled the hub kit apart and it doesn't look damaged either. I was thinking about buying a new hub kit just to try it. Any suggestions would be appreciated.

Sounds like the hub is slipping. All the signs are there! Does it have the quick change hub, or is it the pressed in?

Its the quick change hub. I pulled it apart and from first look it doesn't appear to have any damage. I was thinking about just buying a new one and seeing what happens.

It could be a cheap fix before turning it over to a tech for further damage! I would also drop some of your lower unit oil to see if their is any metal shavings, or a milky look to the fluid. the only way I could see the quick change hub slipping is if the splines on the inside of the hub are rounded off

Ive torn up hubs and all it takes is a thin layer to wear off for it to start sliping, hope thats your only issue!