Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor

   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #1  
G

Griffin77

New member
Joined
Nov 23, 2022
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5
Tractor
John Deere X340
Hello Everybody,

We're at wits end and are hoping that somebody knowledgeable here can please help with this. We have a leaking water pump in this FD731V Kawasaki twin and John Deere lists all the various seals and the pump cover and impeller, but the impeller shaft itself doesn't come up on any of their parts diagrams. Ours is pitted and we'll loose the motor if we can't rebuild the pump as no point putting new seals in with a bad impeller shaft.

Does anybody know even the Kawasaki part number for the impeller shaft in this FD731V Kawasaki motor? The full motor model is FD731V-DS02, but an impeller shaft from any FD731V series should fit.

Many thanks.

Griff
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #2  
I have always just replaced the whole pump vs trying to rebuild.

If shaft is pitted what does the mating housing or bearing surface like?
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #3  
Griffin77 said:
Does anybody know even the Kawasaki part number for the impeller shaft in this FD731V Kawasaki motor?
Click to expand...

I can't think of any maker that currently sells all the internal parts to a water pump. Even getting them apart to replace a seal, shaft, or bearing is often not possible without damage.

This is an aftermarket pump I put in an FD620 on a Gator. It was not expensive, tho not OEM, either. I am not thrilled by Kawasaki's extensive use of plastic on the drive gear, impeller, and cam gear (!). Might be the same as yours.
 

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   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor
  • Thread Starter
#4  
Thank you for the replies so far.

FD731V has the impeller shaft built into the engine casing and the pump components (3 seals and the impeller and impeller bolt) go onto the captive impeller shaft.

All the seals and impeller are still available from John Deere, but they don't even show the impeller shaft on any of their parts diagrams, hence being unable to order one.

The FD620 pump won't work unfortunately.

The mating housing is also pitted, but this is also readily available new. It doesn't make sense that there is a listing for every single water pump component except for the impeller shaft. It's not discontinued; it just doesn't show up on any parts diagrams anywhere and I'm stumped...

Hoping somebody who has experience with this motor might be able to chime in?
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #5  
Griffin77 said:
The mating housing is also pitted, but this is also readily available new. It doesn't make sense that there is a listing for every single water pump component except for the impeller shaft. It's not discontinued; it just doesn't show up on any parts diagrams anywhere and I'm stumped...
Click to expand...
The only explanation I can think of is that the shaft is included with one of the other parts, esp a part that has to be pressed onto the shaft.

Do you have a friend with a lathe?
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor
  • Thread Starter
#6  
dfkrug said:
The only explanation I can think of is that the shaft is included with one of the other parts, esp a part that has to be pressed onto the shaft.

Do you have a friend with a lathe?
Click to expand...
You're right. The reason the shaft doesn't come out is because it is part of the camshaft (extends out from one end)! A crazy design in terms of lack of serviceability, but efficient to manufacture. So, need to remove the camshaft just to rebuild the water pump by machining the impeller shaft that is on the end of it (or otherwise replace the entire cam if didn't have lathe access).

Once it is machined, how does one build up the shaft again to the original diameter for the mechanical and oil seals? Is there a specific material that should be used for a bushing or sleeve? The shaft itself would have been hard chromed when it was new.

Thank you
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #7  

​
Griffin77 said:
You're right. The reason the shaft doesn't come out is because it is part of the camshaft (extends out from one end)! A crazy design in terms of lack of serviceability, but efficient to manufacture. So, need to remove the camshaft just to rebuild the water pump by machining the impeller shaft that is on the end of it (or otherwise replace the entire cam if didn't have lathe access).

Once it is machined, how does one build up the shaft again to the original diameter for the mechanical and oil seals? Is there a specific material that should be used for a bushing or sleeve? The shaft itself would have been hard chromed when it was new.

Thank you​
Click to expand...

I was going to suggest a speedy sleeve for the seal area if that is all that needs to be reconditioned. Otherwise, a machine shop would spray it and machine it.
​
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #8  
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   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor
  • Thread Starter
#9  
TractorTech said:




I was going to suggest a speedy sleeve for the seal area if that is all that needs to be reconditioned. Otherwise, a machine shop would spray it and machine it.
​
Click to expand...
Thank you for the help, and for the welcome. This is a great place
 
   / Kawasaki water pump impeller shaft in FD731V fitted to X520 lawn tractor #10  
Did you get a shaft yet?
 
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