sharpening impellers?

[Bait O' Eggs]

Does anybody know how to sharpen an impeller on a pump?

I have a 115 HP Yamaha outboard with a pump. I am going to try and tear it apart and sharpen and shim it. The shimming seems pretty easy.

When the impeller is sharpened is it at 90 degrees, or is it beveled to one side? I would think it might look like the front edge of a airplane wing when done properly. maybe it works better when it is 90 degrees.

Any help would be appreciated.

[This message has been edited by Bait O' Eggs (edited 01-21-2001).]

[Mr. Fisherman]

BOE,

No Nookie for you

Heard that a guy from Duckworth knows everything that there is to impeller sharpening if ya can wait out an answer while folks in line for gasoline reload their hand guns .

Pilar,
I heard that Roy's date couldn't swim and got nervous when the Coast Guard pulled out their swift response boat with a broken p.a. speaker and trailered it home .

Roy, Look at a new impeller. Take a gauge and check the angle. From there if may be simple. I would recomend taking a little at a time so that you don't throw off the balance. It might be a good idea to buy a new one and then try sharpening the old one just in case.

Hope all is well. Give me a call when the bow of your boat dries out again.

------------------
Live to Fish
Fish to Live

Roy, I've sharpened my own impellors many times. I was shown many years ago by the guys at Steven's Marine. The the pump impellor blade's leading edge (that point down into the water) should be flat and the upper edge is filed at about a 30 degree angle downward to a sharp point with the underneath side. That way the water is cut and directed up into the pump. Use a fine grade file so as not to take too much metal off. Be sure to use the silver "whatyamacallit" pump seal grease on the rim of the pump housing before tightening it back on again. If you get a new one, consider the extra layout for a stainless steel 4 blade impellor. They increase performance and are much harder to dull and ding up. Then sharpen the old one for a spare. - Steve

[Bait O' Eggs]

Thanks for the help. I got the impeller tore off and found that the sleeve is toast. I could lay a dime in the sleeve, maybe a quarter and the impeller would not even hit it. That is some serious pitting in the sleeve. I think I was losing a lot of water. Gotta quit running it thru the sand I guess

Off to the store tomorrow for a sleeve and maybe a new impeller. I melted the plastic sleeve heating the impeller up to get it off.

[MikeT]

BOE,
I've got the same motor.
I keep the impellor sharp by periodically touching up the leading edges with a file. I maintain the same angle as was originally put on the impellor, and try to get a sharp, straight leading edge. So far I haven't noticed any problems with this.
For major dings I have a pro take care of it.
Not sure your idea of shaping the edge like an aiplane wing is a good one; I'd check with an experienced tech before changing anything from original specs.
Hope this helps.

regards....MikeT

[Pilar]

Bait of Eggs! What no crab on? Are you having a bad boat day? Thought you had a date with Tillamook Bay today. Just checking on you bro. Take care.

The bend is your friend!

[Bait O' Eggs]

pilar - My date got mad at me and threw out of her house. Her dad Mr White Cap was chasing me all over the bay beating on me. She didnt look that good, maybe I needed a few beers for courage.

Mike T - I am not sure of the original angle. That was 400 hours ago and it has never been touched with a file yet. It doesnt really have an angle left on it, sort of all smushed over each way.

[boater]

sharpen it like a lawnmower blade, when you have it sitting on the bench sharpen only the bottom of the blades, you want the top to be flat, if you sharpen it like an airplane wing you will be diverting water away.