Removing galled superjet impeller

[topnitroracer]

I have a one piece skat setback pump with what is most likely an impeller galled to drive shaft. The skat impeller finally broke free, but still extremely tight and notchy when it does move. I also destroyed the skat hex impeller tool in the process. I am currently waiting on getting two more tools I just ordered.

What have you guys generally done to remove galled impellers? I am assuming cutting them off vs. trying to continue to unscrew them? My thought is thin hack saw and/or carbide burr tool to slowly split the impeller from the shaft. Things are tougher because it is one piece and setback. Wanting to limit potential additional damage to the shaft, but it still may be already toast. This is going to be an expensive, proactive pump rebuild, haha. This is the first time i have attempted to remove the impeller since I bought the ski.

Also, what are your experiences with the skat impeller tools? They just seem really weak and deflect WAY too much. My hex tool eventually buckled on all sides using a box wrench and cheater bar - which is the minimum you need to have the wrench and tool to keep its shape. I see fast elements supposedly has has a stronger, extended one made of tool steel (their site no longer states this though) Not sure how those have worked for anyone. To be fair I was using a 12pt box wrench, but since then I have purchased a 6pt box wrench - and also a 1-inch drive, 6pt 22mm deep impact socket what I can either put flats on or use my huge pipe wrench. The 1" drive allows the shaft to fit through the drive square.

Any thoughts or insight would be appreciated. Thanks!

 

[iQRTurbo]

The impeller tools are weak and because they are hollow to pass over shaft collapse easily. I tack weld a large nut to to the nose of the impeller that you can get a bigger box end wrench onto. 3/4 “ nut drilled out to 3/4” ID works well. (1 1/8” hex not a 1/2” nut that uses 3/4” hex like most dumb dumbs refer a 3/4” nut too). If you save the wheel you can grind the nut off and clean it up with a flap disc wheel.

It will allow you to put monster torque to the wheel but if it is galled it’s as good as permanently welded to shaft and impeller and shaft are both likely junk. Now it is truly about trying to save the pump but still need impeller off so get busy!
Impellers suck to cut off in a setback one piece. Start by grinding a blade off to make room to get at the hub and when you get pissed off take a break and come back later.

 

[JetManiac]

It sounds like you have good tools and the technique down. We tried a fast elements tool here in the shop on a tough one, and messed up the tool on the first use.

We have usually just welded on a wrench. As iQR said above, when prop and shaft are galled, usually both are toast anyway.

 

[Wetbuffalo]

The Torrent one is awesome. I would maybe get one of them. A proper machined tool, not cast crap.

 

[iQRTurbo]

That looks like a three man job

Here’s how I hold the shaft,
Soft jaws machined to the O.D of the driveshaft for a Kurt high torque machinists vice. You can hold right against the impeller tool (or nut welded to impeller on galled setup)
Absolutely zero slip, no torsional twist in driveshaft from holding it 30” apart so you get full torque. And it holds everything solid while working. Have a 2” receiver on mine too for traveling impeller changes

 

[vomitspot]

That looks like a three man job

Here’s how I hold the shaft,
Soft jaws machined to the O.D of the driveshaft for a Kurt high torque machinists vice. You can hold right against the impeller tool (or nut welded to impeller on galled setup)
Absolutely zero slip, no torsional twist in driveshaft from holding it 30” apart so you get full torque. And it holds everything solid while working. Have a 2” receiver on mine too for traveling impeller changes

what is keeping the shaft from slipping ?

 

[iQRTurbo]

Just the pressure/clamping force from all the smooth surface area of the jaws. Kinda like a collet on a mill or lathe. I’ve never had the shaft slip in it even on a galled impeller with a nut welded to it and a cheater pipe on the wrench

 

[Notrimflippah]

I have a few questions if you guys don't mind. I am trying to figure out how to change the bearings and seals on my pump. I have a Yamaha 61x motor and 144 pump in a 2016 eme aerial 8 hull. I just ordered the tool to remove the solas impeller and the holder for the drive shaft. I noticed last night that the drive shaft looks like it is custom made. It looks like it is welded about 5 inches before the splines and the rod diameter increases at the end. Wich is leading me to believe that once I get the impeller off that it will not slide over the end of the driveshaft. Can anyone confirm if this is a stock driveshaft and explain how it comes apart.

 

[JetManiac]

That is a oem stock SJ driveshaft which is tapered in the middle. There are 2 welds on oem sj driveshafts, one near the splines and one in front of the impeller. Prop will slide right off.

 

[Notrimflippah]

That is a oem stock SJ driveshaft which is tapered in the middle. There are 2 welds on oem sj driveshafts, one near the splines and one in front of the impeller. Prop will slide right off.

Thank you! I was starting to get a little concerned, this is my first time doing a pump and midshaft rebuild. Any tips or things to watch out for?

 

[jetfreak78]

Thank you! I was starting to get a little concerned, this is my first time doing a pump and midshaft rebuild. Any tips or things to watch out for?

Get a superjet Service manual....