Yesterday, while returning to the Marina, the engine or I/O Drive started banging, but only at higher RPMs ?

Question

As soon as I lowered the throttle it stopped. My first thought is this seems serious, but now I'm thinking there are probably many, not so serious reasons this could be happening.

Answer 1

I/o`s can be expensive to repair.I would not run it again with a load  till you find the prob. might cause more damage. more money.

Answer 2

Engines don't bang unless there is some wrong>Best take to the repair shop and have them check it out before you use it again>

Answer 3

Have to agree with 45cal, banging noises are general a bad sound.  

Get it checked out, do not risk going out again until you get it looked at.

Good Luck and Boat Safe ! !

Answer 4

The problem could just be a faulty rubber hub in the propeller centre replacing the prop. or this hub could cure the problem. Also there is a small gear called a clutch dog that slides front to back on your propeller shaft in the bottom end of the out drive section.  It has 2 small flanges on the inside of the front of this clutch dog and 2 on the inside of the back, these flanges lock into a similar flange on the forward and reverse gear which is pressed onto the prop. shaft. over time these flanges wear out and will cause the clutch dog to pop out of the flanges, the parts to replace this clutch dog are fairly cheap but the propeller shaft has to be removed to fix which can be fairly expensive.    

Answer 5

I suspect major problems, but your description leaves a lot of unknowns.  Practically all of them would require a mechanic sometime to identify.  Keep in mind that the mechanic starts with what you tell him, so the more information you can give him, the less you have to pay him to look.  If for example you think you might have hit something, underwater, he would check the drive, where if you were almost out of fuel he might check the carb and filters first.  Good luck!