Another dang FX1 pump thread......

[adet16v]

Sorry..........probably won't be running this ski until spring. I just wanted to see if it was feasible and I think it's even easier than I thought. It's definitely the path I'm taking for my new FX. I think the 140mm pump will be sufficient for my motor (stock 61x with a factory pipe) and I'm sure it will handle more motor than what I have.

I think it's the easiset way to get better hook up and if you can find a good used pump (and they seem pretty plentiful) than it's probably the cheapest way as well.

Here's what's required:

650 pump/prop
900 zxi shaft
X2 tilt nozzle
Kawasaki bearing housing (can be from any model and can be junk as long as the bearing/seal surface is good)

If you're serious, I'll machine the Kawasaki bearing housing and press it into the Yamaha housing for you if you send me the parts. I'd like to see someone else try this as well.

seems as though I may have just found a winter project. :biggrin: I currently have an 87 x2 that I am parting out (was my first ski) so that supplies me the pump/skat prop, tilt nozzle and bearing housing.

I was planning on parting out the x2 and selling my fx-1 sometime next summer to put towards a RN SJ... I have just become so frustrated with the lack of hook up in the fx-1 pump and it seems as though conversion to the yamaha 144mm pump costs in the range of 800-1200 dollars which just doesnt seem worth it to me when i could sell my fx and buy a RN for 3k.

I agree that the 140mm kawi pump will definitely handle the power significantly better. I dont think it would have any problem at all.

 

[special fx]

Just a couple of updates........I finished fitting the pump to the hull, drilled the mounting holes and glassed in the thread inserts (I used Kawi stainless hex inserts) and added a thru-hull fitting/tube for a trim cable. T

It's pretty much ready for some silicone and a test ride! (If the ice would turn back to water)

 

[adet16v]

Is that an extra thru hull fitting I see for trim? :sneaky:

Is that also still the stock steering cable?

Looking Good!

 

[special fx]

I also modded an R&D pump cone and 800 SXR prop to fit the 650 pump. To make this work you need to fabricate a 4mm spacer to fit between the cone and the rear surface of the stock hub. With this mod the cone fits great.

The SXR prop needs to be machined to set it back into the 650 pump. I set it back 6mm, but it could go further and not interfere with the pump cone.


I'm not going to run with this pump cone/prop at first, cause I want to get a good baseline utilizing a stock setup and then run this to see how much difference it makes.

 

[special fx]

Couple more pics showing the SXR prop and the amount of trim available from the X2 tilt parts. It also shows the fitment of the FX-1 scoop grate to the 650 pump, it actually bolts right up.

 

[special fx]

One more pic...........This shows the bulkhead bearing and the trim cable tube at the firewall:

 

[special fx]

Yup, trim cable mount (using stock steering cable hardware and 1/2" treaded pipe) and yeah, that's a stock steering cable. With this combo of nozzle, trim and steering nozzle, the stock cable and ratios are maintained.

 

[special fx]

Here's some info on what needs to be done in regards to pump mounting. The FX front mounts are raised as compared to the rear mounts and the Kawi pump uses a flat surface.

So, you need to remove about 5/16" of material at the area of the front mounts (marked on yellow in the first pic) and then the rear mount area needs to be built up around an 1/8" (marked in red) and leveled side to side (the stock FX mounting surface isn't level, it slants down towards the center. When fitting the pump, the apex of the rear pump cone should be 3.5" from the surface of the flat area between the mounts and the front of the pump should lay right into the little recess left by removing the stock pump shoe. Also, it should be centered side to side (just to state the obvious!)

Ok, now you have a flat/level mounting surface that's the right height, so now it time to drill holes and put the threaded inserts in. I filled in the stock recessed areas and started over. In the second pic you can see where they need to be compared to the stock FX locations. I used Kawasaki stainless hex inserts, but you can re-use the stock FX bronze inserts with no problems.

Other than the glass work for the mounting area, a little grinding is required in the pump shoe area as well. I also ground a little material off the pump itself to minimizw the re-work to the pump inlet area. All in all the mod is pretty easy.

 

[kiwifx1]

Hi
My first post.I've only just found this thread,but it's extremely informative and very encouraging.I've been freestyling an FX1 for 13 years and love this ski,grew up on the old 440's.I'm real keen on doing this mod,but I'm also very interested when you get it in the water and how it performs before I go chomping everything up.I don't have a spare hull.I'll start collecting the parts.

What is the overall measurement of the 900zxi driveshaft?

Awesome article,fantastic photos,Thanks.

Cheer's Steve.

 

[special fx]

Ok........Finally an update!! The weather finally broke and gave me a chance to test out the ski. Well, it works great!

Hook up is WAY better than the stock FX. I took it into the waves and went searching for white water just to verify the lack of cavitation. The FX pump would simply spin in white water where the ski now hooks up great. It didn't change the way the ski handles except it feels maybe a little more responsive in the steering dept. That may be due to the steering nozzle pivot being slightly further back than stock. The steering felt very light and responsive and wide open runs on flat water showed no odd tendency in handling (Yeah!) and I don't think it has any negative affect on top speed.

To get a baseline, I put the ski together with a stock Kawi 650 pump and a skat 650 prop. I'm also running a bone stock 701 61x with a factory pipe and stock ignition (although I jumpered the rev limit).

My next step will be to run it with a R&D pump cone and SXR prop. I'll try this with the same engine setup and see how it works, then I'm going with a mod motor.

 

[adet16v]

Thats great JD.

I just finished blue-printing my pump and I rebuilt it (new bearings/seals etc.)

I still need to finish the glass work (waiting for a warm day) and then Ill be all set.

How did the bottom end feel? Much better?

 

[special fx]

Definitely better on the bottom end! In fact, I couldn't really care less about top end but it's good at the top too. Again, it's only a totally stock 701 engine but I'm impressed with how it responds from idle when you punch it.

One interesting thing is that with a stock FX pump there's no way you can run a factory pipe without a rev limiter mod and when I did my rev limiter mod for this ski I put in a switch so I could turn the stock limit on or off and with this pump it handles the stock rev limiter just fine. Bottom line, it loads the motor better and brings the Rs down.

 

[special fx]

I was so phsych'd about how the pump worked I forgot to mention what didn't work........my trim system doesn't do sh*t! :banghead:

The best I can tell it's due to the fact that under full thrust load the cable (bicycle brake cable) just stretches. The nozzle motion is great when it's not running but under load it doesn't even move. I think if I give a sh*t about trim I'll have to find a stronger cable.

 

[special fx]

OK.....another update.

After getting a baseline with a stock 650 pump and a stock 701 w/FPP, I wanted to go to phase 2 and check results. Phase 2 of this project is to use a 650 pump modified with a R&D pump cone and fitted with a set back 800 SXR prop.

I set up a new pump with the pump cone and sxr prop and then swapped pumps in the FX-1. I wanted to see what this setup would do with a stock engine before going to something more rad.

Well, I gave it a water test yesterday and Holy Sh*t!!! The R&D pump cone/SXR prop combo is absolutely kick a$$. I thought it would overload a stock 701, but it totally made it come to life. I can't believe a pump mod can make that much difference but it does!

OK, time for paint and turf and on to phase 3......a mildly modified 61x motor............stay tuned!

 

[adet16v]

JD, If possible could you measure this distance for me? From the wall of the pump cavity to the center of the first mounting hole. THANKS. From your writeup I believe the pump should butt up into the recess left from the stock shoe.

With the rideplate installed, should the kawi pump shoe be butted right ap against it or should there be a small gap?

 

[oxnard111]

Freakin sweet. Diggin the updates. If I had an FX-1 and I wanted to do a pump mod this would defiantly be the way to go.

 

[special fx]

I'll try to get a measurement for you, but the simplest way to set the location (front to rear) of the pump is by bolting up the scoop grate.

The pump should bolt up to the FX scoop with the bolt at/or near the rear most part of the scoop grate bolt hole. On mine, this leaves the pump about 1/16" to 1/8" from completely bottoming out in the recess left by the stock FX pump shoe. Aside from positioning the pump for you, it will make sure you can put your scoop grate on without hassle. It's just dumb luck that happens to be the exact position of the pump, but why question success! :biggthumpup:

 

[adet16v]

OK, that makes sense, With the bolt for my scoop grate at the rear of the slotted hole it leaves about 1/4" to 3/8" between the recess and the Kawi pump. Nothing a little 3M or caulk cant fix. Guess Im ready to drill my holes.

No need to worry about the measurement JD.

My next question... how did you go about pump alignment and motor alignment?

Im thinking bolt the motor down with the shims in their previous locations and then align the pump (using shims if necessary) to match the motors location... see any problems with that?

 

[special fx]

As far as alignment, if you set the front of the pump so that it sits in the stock FX pump shoe recess and then set the rear of the pump to measure 3.5" from the flat surface of the hull to the apex of the pump cone at the rear. This can be achieved in different ways. I built up the mounting area with fiberglass to eliminate the need for shims, but you could simply shim it to gain the same result.

I set mine up this way and only needed a couple of shims on the engine mounts when aligning the couplers. It needed less shims than the stock setup.

 

[special fx]

Here's a pic of the rear measurement for reference: