07-23-2010, 06:03 PM #1
Can someone explain this to me once and for all?
I wasn't going to start a new thread on this but I just don't get this and I need to get some clarification before I lose my freaking mind.
I got the broken piece out of the stub shaft out of my 371 swirl impeller. As you can see in the pics below the impeller doesn't seem to have any damage other than some small burrs I removed from one blade. The splines and threads are in excellent shape. The outside of the blades are square and uniform. It isn't chewed up. It is the right part number. My wear ring is also in great shape, not even a scrape.
Here is the big question: Why can I fit a 1/2" combination wrench between the blades and the wall of my wear (extension)ring? You can see that the 035 impeller is in there with a nice fit with less than .015 clearance. Is this swirl impeller supposed to go in there like that? I wouldn't think so. I realize I don't have it on the shaft like the 035 is but I should still be able to place it inside the ring and have snug fit while on top of a flat surface I would think.
07-23-2010, 07:22 PM #2
measure the size of the prop. it should be 148mm.. they also make 146mm ones also. for example. I have a 8-vane stator with a small hub and its 146mm.. not 148mm like a stock stator..
or the blades are bent from whatever went thru bending them.. other than that, I,m not sure..
07-23-2010, 07:53 PM #3
This is like alien, UFO sh*t.
07-23-2010, 08:45 PM #4
I thought I would entertain the thought of the blades being bent so I just quickly put it up on a flat surface and marked the ends of the blades as a measurement guide. All the points are the same. The blades are not bent, unless they all bent back evenly. I don't have a metric ruler so I couldn't measure it to see if it was 148mm but it has to be because it is the stock impeller.
07-23-2010, 09:18 PM #5
The impeller was cut to 146mm? to run in a smaller wear ring? It is an odd ball. What is the ID of the wear ring?
07-23-2010, 09:50 PM #6
You're right. Someone had this stock 5131371 impeller brought down to 146mm. The box that it came in said it was 148mm. I found it in the storage compartment with the old impeller in it when I got the ski. Whoever changed it must not have known what they were doing. When I was trying to check the clearance through the intake grate a couple of months ago I didn't know what the hell I was doing either. Again, a perfect example that you need to check everything out thoroughly. More than one person here told me to pull the pump and I didn't listen. Could this have also contributed to my drive shaft run-out also?
Pictured below is the same extension on the 5131035 impeller that is definitely 148mm. which proves your point. Tom was right also. I just can't believe that it ran well at all setup like that.
07-23-2010, 10:31 PM #7
Just think about how much better it's going to feel once it's corrected.
07-23-2010, 10:47 PM #8
07-23-2010, 11:11 PM #9
- Join Date
- Jul 2007
- near Toronto, Canada
One way to eke a little more speed out of a slightly worn engine is to under-prop it slightly, to allow to RPM to get into the engine's sweet zone despite the HP deficiency.
Now that you know how to remove and re-install the jet pump, it won't take long to install and try the 035. You just might like it
BTW, you can measure impeller diameter across the bottom. Or put the impeller between two parallel edges, then lift it out and measure the gap.
Note: Not only were the original 1992-1993 non-modular Polaris jet pumps using a 146mm size impeller, but there were also some unusual racing jet pump configurations that used different diameter impellers.
The Polaris Octane stand-up model uses a 144mm jet pump.
The easiest way for a racer to get a smaller diameter impeller would be to take a 148mm prop of the desired pitch, and have it ground down to the diameter they needed. The blades may also have been bent (tweaked) to create the exact pitch needed for their application.
07-23-2010, 11:32 PM #10
I was going to try and measure that damn thing from the bottom and then I dropped my caliper and broke the damn thing. I have had it since 1983 anyway it was time for a new digital jammy.
It just hit me. If I run the 035 I could be on the water tomorrow. I already have a new drive shaft and that pump is all ready to go.
I am going to take your advice and try it out first. It is better than sitting around the house waiting for UPS to deliver all my sh*t.
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