Broken prop, what to look for when replacing.

[gazelle]

I hit a rock or something this weekend and bent two blades on the prop and broke a piece off the other. I know I need to replace the prop but I was wondering what I should look for to make sure I did not do damage to anything else. I was about a mile away from the dock so I limped it back in. It vibrated more than normal for obvious reasons but I do not think it was to bad.

What should I keep an eye on the next couple of outings to make sure that nothing else got damaged?

A bad storm was also coming in when we got to the dock so we closed up shop and got in the car. It did not occur to me to check the tools that I would need to replace the prop next time out. (repair manual in boat) Can I use the same nut and star shaped washers or do I need to replace them? Roughly what size is the nut to take off? Can I get it with standard sized sockets or wrenches or do I need to get something bigger? Just trying to make sure I have all the appropriate tools with me to ensure I do not get there and have to drive back home for more tools.

1997 force 90 hp.

Thanks
Gazelle

 

[Frank Acampora]

Re: Broken prop, what to look for when replacing.

I'm reasonably sure that that is the Mercury lower unit. You can re-use the hardware. The prop nut is 15/16 nylock. a regular open end wrench can get it off, but a deep socket is better. Aftermarket also sells a prop nut tool--if you are inclined that way. I think you also need a flat blade screwdriver to bend up the tabs on the washer. If it is the one I think it is, the nut sits in a recess in the washer and the tabs lock the washer from turning.

The prop is repairable but with that much damage it will cost a little more. Buy a new or good used one, repair the bent one and save it for a spare.

Once you have another prop on the engine, spin it in neutral and see if the shaft is bent. You should be able to eyeball it --Good or Bad.

 

[skibug]

Re: Broken prop, what to look for when replacing.

If it was an aluminum prop then all should be good. If it was a stainless prop, then I would check the gears and shaft. An aluminum prop will give and fall apart way before the shaft and gears are damaged most of the time.