Changing the Prop?

I'm going to help my buddie out while he is on vacation and get his prop right. I guess he installed a new one and put in on wrong and it is way off balance. I found a prop puller and he was talking about their is a groove in the shaft that has a piece of something that goes into it before the prop is put back on. Now I have not done this before but he said it's not to hard, ya and he did it wrong and now I'm going to try it. He mentioned that their is groves that the prop will only fit one way but not to forget this piece that goes between the prop and the shaft, and is supposed to give if the prop hits something so your don't kill your shaft and prop. Well he forgot this piece and the prop vibrates when you give it gas. Is this a do it yourself project or should I leave it to the boat shop? I have offered to detail his boat inside and out just to say thanks for the pulls this summer and thought I could also get this prop on right so he can use his boat right when he gets back and enjoy the fall riding. I have it for 12 days and think not only I can get it to shine but in working order also. Any advice is welcome please.

it's a "key". The shaft is smooth as is the bore of the prop. No matter how tight the nut is, the prop will eventually slip on the shaft without the key. The slot on the shaft needs to align with the slot on the prop and the "key" inserted. The key will prevent the shaft from spinning without turning the prop. The "key" is just a piece of metal.

Steve ~~ Thanks, now if there certain sizes of these keys or all the same for the make and model? I might need to get his prop size right?

Pull the prop and take it to the hardware store, or Sears, they will be able to hook you up with a key. They are 1/4" square bars normally, but take the prop to make sure. I had to file my key down on the last boat to make it fit in the slot correctly. Some keys have a half moon on one side and a straight side on another. Look at the shaft and prop, if one has the half moon slot in one, then that is the one you will need. Like the above poster said, the prop is slipping on the shaft. It might take some work to get it off if it has been spinning. You might need to sand the shaft, to smooth it out, if the spinning prop created a groove in it. Get 400 to 600 metal sand paper and start sanding till smooth.

Josh-
Sounds like Paul has the ticket. I've only changed mine and kept the same key. I'm not sure about different sizes for different makes.

Paul ~~ Thanks for all the info, I stopped my my local MC dealer due to the Calibria dealer not knowing "S". I told the service guy at the Cal. dealer which boat I have and looking for a prop key and his next question was "which outboard motor do you have?" WTF your kidding right. Well the MC dealer gave me two keys at no charge the square and the rounded ones and offered a demo on their X-15 this weekend. I'm now talking with the GM of the Cal. dealership to let him know about how bad it really is. A lot more then just the service guy screwed up. Thanks for all the posts and I think I might have it with the two keys and I got a buddie that is going to loan the prop puller tonight! Thanks guy's...

What about my awesome CAD skillz??

247 LSV, cad skills are great, what is the caliper for to measure the key, if that's what it is. Or is that a puller? I always use a ghetto gear puller, modified, so I don't know what a real tool looks like.

I have no idea how you could put a prop on wrong. Leave the key out, perhaps, but that would make the prop slip, not vibrate.

Vibration from the prop usually is the result of a blade being bent or otherwise damaged.


Paul: that picture that 247 posted looks like the contents of a prop puller kit: the "c-clamp" looking thing is the puller. There is a wrench, one end for the prop nut and the other end for turning the puller. Spare key, cotter pin and prop nut.


Rod

Paul,

HAHA! Yep, thats a real inboard prop puller. I just got my own a couple of weeks ago when MY key didnt give way to the stump gods

Well I would like to say thanks for all the posts on this thread. I pulled and put back on the prop in just under an hour. They key fit like a glove and the screw is nice and tight. I guess the next thing is to test it out! I will say one of the best things I was told is to put the nut back on for a couple of turns so when the prop gives it wont hit the ground and bend. When it finally gave it made me jump back for the noise and the force as it pop'd off. Thanks everybody!

247: The key is not supposed to give way when you hit something. Some setups, especially smaller outboards, use a "shear pin" that is designed that way. Those pins are are just small diameter pins that insert crosswise to engage the prop and they have very little shear surface.

Rod