Finally hit something... questions

[convergent]

I finally hit something with my prop... actually two things kind of... yesterday. When we went into the lake, they had a sign up saying that the water level was down so be careful. I launched on one ramp with no problem. This lake is small and there aren't really too many places the water level is low after you get 10' from shore, except in the coves.

First thing I did was get the ski harness wrapped around the prop unknowingly. When I started the motor and tried to pull off, we didn't go anywhere, so I turned if off and fixed the rope. It didn't cut the rope or anything, so not sure how that worked. Does that mean the prop spun on the hub?

After we were done skiing and wakeboarding, I did a lap around the lake and noticed that I wasn't getting up to the same speed I usually do, and the RPMs were lower at WOT. I did have more people in the boat than normal... specifically an extra 225 pound guy. I will check again with the normal load to see if that was it, but it seemed odd. If the prop spun on the hub, is that something that has to be repaired afterwards, or is that just a passive failsafe kind of thing?

Then when I was retrieving the boat, I came gliding up to the trailer and hit something, and then immediately trimmed up. I was moving at idle speed, so pretty slow. When I got the boat on the trailer, I noticed the edges of the prop are dinged up. The prop was replaced a couple months ago so it looked new before. Nothing bent, just could tell the edges of the blades had the paint gone and were a tad rough.

How does this happen? If the skeg is sticking down way below the prop, how in the world does the prop hit the bottom? I don't know what is down there, but I don't think the ramp extends as far out as I hit something. I was probably still 50' from the end of the trailer when I hit.

 

[steelespike]

Re: Finally hit something... questions

If the hub worked on the harness and wasn't too abused it will continue to work correctly.If it is weak you will notice it under hard acceleration.Once it starts to fail it will become more and more weak.
As far as the skeg if you think about it it only protects the blade directly behind it
you may have passed an object not directly under the skeg or it could have an irregular shape.skeg could have bumped over something and as it dropped off the blades got nicked. It sounds like you could dress the edges lightly with a file just try not to change the profile.If you think there is any unusual vibration you might have a prop shop give it a look.

 

[convergent]

Re: Finally hit something... questions

In this case I was assuming that what I hit was the bottom, since I was between the loading docks at the ramp, and that's why I didn't understand the prop getting scraped. Is it possible that if the bottom is just sand/muck, that the skeg dug into it? I guess if it were soft enough for that, then it wouldn't have scratched up the edge of the prop.

 

[steelespike]

Re: Finally hit something... questions

Anything could be in the muck.There is only so much the skeg can do otherwise you wouldn't see props with no blades left.

 

[convergent]

Re: Finally hit something... questions

I went back out a couple of times this weekend and the RPM situation hasn't changed with a smaller load of people in the boat. This is really weird. I don't feel any vibration at all, and we are skiing, wakeboarding, and tubing, and don't notice any difference in the pull to get them up. But at WOT, my RPMs are lower than they were before. It used to go past the 5250 max for this motor (I had hit 5500 a few times when not paying attention and still had more throttle left), and now it maxes out around 5100. The speed is down a little too, and it feels/sounds like I'm trimmed too high even though I can't find a place that I'm not... like its slipping I guess. I would think that would make the RPMs go higher than normal, so its kind of odd.

I looked closely at the prop blades again and they are barely scratched on the edges. One thing I notice, which I don't remember if was like this originally is that each blade has a little bit of a cup to it about a 1/2 inch from the end, but they are all exactly the same so I can't believe that happened from hitting something and didn't do more damage than this... and doesn't have any vibration. So my assumption is that it was like that originally. Its not anything I think would show in a picture.

So does this sound like a hub problem? If it is, can it be fixed at a prop shop or is the prop going to need to be replaced. I was planning to buy a new 4 blade prop anyways, but I wanted to try and figure out what was going on with this one in case there was some other problem going on here beyond the prop.

 

[nor2345]

Re: Finally hit something... questions

I know where your coming from convergent...our lake is down and last week I hit the side of a rock ledge out in the middle of a large cove. Trashed the prop but only bent the skeg about 3/16th in. I'll leave the skeg alone but the prop was sent off for a re-build.