Impeller sharpening

Seth

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Outboard jets shows that you sharpen from the top, then the bottom and then smooth out the bottom edge. I've read several times that people say to ONLY sharpen from the top of the impeller. So which one is the right way? I'm going to pull my impeller and sharpen it soon and check the liner and all that good stuff. Also, how do I tell if I need to shim the impeller down? Do I just eyeball it or is there some trick to making sure it's right?
 

fender66

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Seth,

Rather than me trying to give you a proper answer.....give the guys at Troutt & Sons a call. They will help you over the phone I'm sure. They have helped me several times. 800-843-9677
 

bulldog

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That article needs to be gold plated. I sure wish I had that a year ago.

The guys at Trout and Sons are top notch also. They get super busy at times but if you catch them and they have time to talk, they really know their stuff. Every time I go out that way I stop in to say hello.
 

Lil' Blue Rude

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DON'T sharpen your impellers the way the link shows. Always sharpen on the top side of the impeller don't sharpen on the bottom of the blade like the link shows. Last fall my brother bought a used impeller sharpened the same way that the link that was posted shows for is 60/40 evinrude. I didn't think anything of it and I put it in shimmed it up and went to the lake to gps it with the new impeller. It would not come out of the hole, it would just set and spin out. You had to ease into the throttle to plane it out. I brought the motor home and and pulled the impeller out and then sharpened it on top like I normally sharpen an impeller. It would jump right up on plane and it gained it 3mph on top. I've heard of this happening time and time again to people. They sharpen on the bottom and their boat just spins out after that. They have to go back in and sharpen it on the top and the problem is fixed. That's why I say don't sharpen the bottom. Think of it like this, if you sharpen on top it makes it easier for the impeller to pick up the water. Wish I could think of a better way to explain it. Tried to post a pic but it won't let me.
You can call me crazy for only sharpening on the top all you want to, but you've been warned.
 

Seth

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Now I am confused. Isn't it saying to NOT sharpen the top on the Snyder boat link? Outboard Jets diagram shows sharpening from the bottom also. What makes the motor spin out if you sharpen like they are showing?
 

optaylor823

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I have always just sharpened one side of the impeller. It would be the top side if you turn the impeller upside down. Also there is a DVD out showing the steps on the 30 minute PM. It is on Backwoods Angler TV site. The cost is 12 dollars plus S&H. Here is the link. https://www.backwoodsangler.com/sponsors%20page.htm
I am not sure but I believe Chris Gorsuch helped put this together. Chris is a great resource for jet information, which he has helped me plenty of times over the phone.
 

Lil' Blue Rude

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When I say top I'm talking about the top of the blades as the impeller sets in the jet pump. I call the side that you can see when looking through the shoe the bottom. I don't know what causes it to spin out when it is sharpened on hte bottom but it does. My brothers boat,my uncles boat,and my freinds boat all had the same promblem when the impellers where sharpened on the bottom, once they resharpened them on the top it fixed the problem. Like I said I'm just warning you guys. Do what you thinks right it's all about trial and error with outboard jet boats, make your mistakes and learn from them.
 

optaylor823

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Ok here is the answer straight from jet outboards FAQ. https://www.outboardjets.com/pdfs/IMPELLERSHARPENING.pdf. I am not trying to start anything just trying to help. I would say from what they are saying you can file both sides as long as you get the correct edge.
 

Seth

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Lil' Blue Rude.....do you smooth out the bottom after sharpening the top like Outboard Jet's shows or only smooth out the top?
 

Lil' Blue Rude

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I'm putting a picture of how I sharpened my new impeller and a picture of a used impeller that I had sharpened. The new impeller has only been sharpened on top of the blade.The red arrows show where I began and ended it. I normally try to go a little farther back then that to make it a very smooth slope. The second impeller was sharpenend on the bottom when I got it. I marked where I sharpened the top with red arrows. The green arrow shows where the lead edge is, in the picture it looks like the lead edge is higher but it starts where the green arrow is. Because the impeller had been sharpened on the bottom I would have had to remove to much material to sharpen it like the new impeller (the blue line shows this) so I blend the bottom end taking as little out as possible. That's the way I sharpen a new impeller and and how I fix a impeller that's only been sharpened on the bottom.
 

moelkhuntr

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Thanks for the pictures Lil' Blue Rud. I was sure that was how your were describing your sharpening. Is that the way the vast majority of you racers sharpen the impellers. What do you guys use to polish the impellers with. Are you using drills with emery wheels are dremel tools with wheels are just good ole plain elbow grease and a lot of time. I have been told by others that a mirrors polish job makes a vast improvement after sharpening the impeller.
 

Lil' Blue Rude

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I don't really know how most people sharpen their impellers? As for the polishing, some good old elbow grease. I started out by doing my sharpening then I'll file any casting marks out. The I sand it down with 180,220,320,400,800,1500,2000 and finished it off with some mothers mag wheel polish. I couldn't tell a diffrence in performance after it had been polished. Looks good though. :mrgreen: I need to take the mothers to it again. Polishing the pump helps. Kind of a pain to get in it though.
I'm begining to think the reason that outboardjet and most people sharpen their impellers on the bottoms is because they see a rise in their RPMs because it isn't catching the water, so they think their going faster because they gained RPMs. Like I've said in previos post i've seen a 3mph gain from sharpening the top of an impeller that has only been sharpened on the bottom.
 

bulldog

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You guy have just saved me a ton of trouble. I'll be remounting my motor this weekend and going through the pump along with sharpening the impeller. Thanks!!
 

Seth

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Thanks for the pics Lil Blue Rude. I'll sharpen it that way and see how it goes. How much speed do you gain by polishing the pump? I've read about guys doing that, but I just don't really know if it's worth it. Seems I suck rocks up pretty often when I start running a lot of a new water.
 

Lil' Blue Rude

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I don't know how many mph it will gain you, it depends on your set up. I didn't run my motor before I polished my pump so I don't know how much it gained me. If you suck alot of rocks I would say it defeat the purpose of polishing it,plus the large pumps are a pain to polish because of the brace in them. If you still want to do it you have to pull the pipe out of the pump and remove your bearing carier out to make it easier. Make sure not to make the opening where the water exits bigger then what it is. On another note if your motor got the grunt to pull a stainless impellers seem to help some to, it gained me another mph with my motor.
 

optaylor823

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Ok I will admit that I only do my impeller about once or twice a year and it is coming up time to do it and I will try Lil Blue Rude's technique and see what happens.
 

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