FX-1 well here's what a bored out stock pump shoe looks like

[MNTURBO]

I don't want to install a 144mm superjet pump shoe because of all the work it takes for fitment, and getting the angles right. Here's a 122mm pump shoe that I reinforced with JB Weld, and then had a machine shop bore it out to 137mm. The intake cavity is about 135mm, so not having a full, 144mm pump shoe shouldn't matter

This shoe should line up and fit perfectly; but only once I grind away some fiberglass to make some clearance for the beefy top section

let me know what you think and any suggestions you have!

 

[yamanube]

Think it will work? Would be cool to use that as a plug and get a mold made to cast up a solid one.

 

[MNTURBO]

I think it will, I was hoping to hear what you guys think.

Since there are so few FX-1's out there (and only half of the pump conversions are yamaha 144mm), I don't think making a cast piece would be worthwhile

 

[tom21]

you will want to smooth the cut into the intake area. Then your issue will be how much meat is left for the intake grate to bolt into. I did essentially the same thing on a few skis but by hand with a grinder. its not fun or quick! depending on your rideplate you will most likely need to do some grinding to make that fit and there is some welding to get the pump to fit also. but it will make a big difference. plus its easier and cheaper to maintain a yamaha pump IMO. good job.

 

[tom21]

I just went and looked at your build, no pump install worries for you. just red loctite that intake bolt and silicone or 5200 that bitch in as well!

 

[MNTURBO]

Thanks Tom21, I'll be sure to smooth out that transition

Do you think I need all that JB weld on the top band, or could I grind it down to make installation easier?

 

[tom21]

I wouldnt be concerned with it too much, I am more worried about the lower portion.

 

[just joe]

Several years ago A friend of mine did some modelling of the intake cavity to determine effects of various shoe sizes when using a 144mm pump, as I was deliberating which path to follow (stock shoe up to 144mm shoe). We looked at flow and velocity and determined that ideal is the 144mm shoe (spent hours with a computer model for that shocking answer). However, transitions made a huge impact. If you have any steps into the pump, then it will create a low pressure region behind the step leading to cavitation through the pump. Make sure the transition from intake cavity to shoe to pump is as smooth as possible. Also measure your intake track... the shoe does not need to be any bigger than the smallest diameter in the entire path to the impeller.

Keep the ski from salt water. The JB weld is porous and oxidation/corrosion on the alum shoe will eventually cause the jbweld to break away, especially since that area sees very high water velocity.

 

[MNTURBO]

I have no doubts that a 144mm shoe would be more efficient, but my pump hooks up great with a 122mm shoe right now (with a little silicon after the shoe) and I just want to get a little more efficiency, without having to widen the intake cavity or mess with pump and shoe fitment

thanks for the insight. I'll definately make sure not to have any steps, other than going from 137mm to the 144mm wear ring. I already have the bottom section of the shoe ground for a smooth transition. Also I was considering giving the pump shoe a few coats of rattle can epoxy paint on the shoe to seal in the JB weld - couldn't hurt

 

[gsx1r1000]

Hey man I am doing the same pump swap. How did you get your shoe out of the ski. It seems like it was glued from the factory. Its marked and ready to be boared out.

 

[Idok]

yoiu have to pry/work it out...it might break

 

[motoman96]

a heat gun helps alot getting the oem shoe out.

 

[MNTURBO]

Update

I installed the bored out pump shoe today. The installation was very easy and only took about 3 hrs. Once I had ground away some fiberglass to clear the beefy top section, the pump shoe bolted right up.

I tested it out and it works great. The pump is now quieter, and the ski is a bit more responsive

 

[MNTURBO]