After a prop. replacement and skag repair my boat wont go over 8mph?

Question

the marina repaired my 3.0l i/o with a new prop,hub and welded a new skag. now over revs when accelerationg. what happened?

Answer 1

The clutch in the prop sounds like it is slipping- have it checked out and replaced if necessary.

Answer 2

Sounds like your boat is cavitating.  Is the propeller they replaced your old one with is the wrong pitch, it can be causing this.

Take it back to the marina and tell them this, they may have put on the wrong prop, or one that is damaged.  

The replacement skag has little to do with cavitation.

What worries me however, is it sounds like you ran over a submerged rock, log, sandbar, another boat? etc.  There could be some damage to the driveshaft within the outdrive unit... if this is the case the cost of repair would be higher if you have a broken or stripped shaft.

Answer 3

Sounds like a faulty or incorrectly installed hub in the prop.

Answer 4

Sounds like the wrong prop was fitted. Check that it is the same as the old one. It may have the wrong pitch on the blades.

Answer 5

Let me recap.  You hit an underwater object.  The service shop found a bent prop and broken skeg.  But, now the boat will not run as before.      I think that there's concealed damage.  If your engine has a thrust hub, mounted on the flywheel, I think it spun.  That means that once a load is placed on it, it slips.  Thus no speed.   This is normally an insurance repair, but I'd take the boat back to the repair shop and let them check it out.