FX1/144mm Bottom Replacement

[Flash-FX]

Ok...This build is the outcome of a "lot of talk/concept" that was bouncing around for a good many years now. When this idea of replacing the pump in the FX1 for better surf riding was discussed, it allways seemed to end with a lot of ?????????????????'s. I needed to check this out.

In the beginning....About 2 years ago, I bought a spare FX hull for a 144mm conversion. Just as a experiment. Since then, That "drop in" conversion got put aside for a complete bottom treatment that blends things together. I wish there was a easier way. But wait...First a couple of things...

#1- I just want to ride.:cheer: ..I hate working on this stuff.

#2- I am not a boat manufacturer.

#3- I do not plan on making boats/parts for sale.

#4- I built this thing because I could not buy one.

It was a boat that the previous owner had tried a 144mm conversion before. He said it really didn't work well."too much cavitation" so he re-installed the original parts, then sold it.

 

[Flash-FX]

After a lot of rough calculations, I decided something more than the graft was necessary. Also to use as many SJ parts, driveshaft,grate,shoe..ect as possible. A Mag 144 1" setback pump ended up fitting just rite. If I used a stock SJ pump the firewall/motor combo is moved forward only 1". There is also a issue of not enough side clearance for stuff. No problem...make more space.
The nozzle pivot is only moved rearward 1 3/8". Since the SJ nozzle is shorter, It
sticks out the back about the same as a stock FX. "Secret Specs". :sneaky:

The goal was not to mess up the FX handling properties too much.

 

[Flash-FX]

To make sure everything fit properly, a short block w/new mounts was used during setup.(Perfect alignment is key). Since the SJ pump shoe width is 1" wider than the FX, the bottom needed to be widened to match. Here's where Divinylcell foam is your friend....easy to shape,sand and work with. Also easily formed with a heat source. Good with the bad...Expensive.

 

[FX-6.9 Boy]

right on, that's my kind of thinking, if you can't buy it figure out how to build it,, very cool.

 

[Slug]

Thats what I plan on doing next winter. I'll still use the coverted pump but I'll replace the intake duct area and pump shoe.
Are you shaping the intake duct yourself or are you going to glass one in from another type of ski?

 

[Flash-FX]

Here's where I formed the intake duct. After much research on design, more :sneaky:. This turned out to be the easiest way. Using strips of foam to rough shape the duct.(instead of pouring a big blob of foam and sanding it down). I failed to mention there is a EXCESS of SANDING that follows a project like this. Some of you already know....Don't forget to wear your mask.

 

[Slug]

wow that's looking good. what type of ride plate are you going to use?

 

[joe b]

Hey MacGyver,
Whens the lamey going in??? I want a ride:biggthumpup:

 

[Flash-FX]

Good question Slug. Now here's where if you are tired of that regular old ride plate, just build a new one. Since I opened up the pump cavity and made the 144mm SJ pump shoe to fit, a custom ride plate was in order. Once again, fun with foam. See where I'm going with this, The foam is not really the finished part. It is for a prototype "plug".
I can see all you SJ guys making custom "backflip" ride plates now:bigeyes: . It really is not that hard to do. Get out there and Sand...Sand...Sand.

 

[GDFL]

Very impressive work. Looks like a custom ride plate is in my future:sneaky:

 

[tom21]

At first I was like why? why not get another ski instead? But you make it look so easy. can't wait to hear how it works. very cool.

 

[Flash-FX]

Now for more...Since the ride plate plug was pretty much established, it was time to refine the overall condition of the hull. Every boat is different, even though they might have been formed from the same mold at Yamaha. The final assembly at the factory is never is exactly the same. Did you ever notice the sides of your boat, where the "bulge" from where the expanding floatation foam left distortions? Well, I block sanded most of that out and restored the overall shape to the "original factory dimension". More sanding...:banghead: :banghead: :banghead:
After you get the finished surface really close with the "bondo" type filler, the next step is to move to a sandable primer. Duratec surfacing primer,(catalized polyester type) is some remarkable stuff to work with. It has a 20 minute pot life, fills really good, cures hard, and best of all sands EASY! Wow..some amazing stuff. More on that later.

Now since this hull "plug" is almost shaped where it needs to be, it's time to make a flange so that the final glasswork (in the mold)has a little overrun area and a place to seal up the parameter. Vacuum bag stuff. More divinycell foam... Glue it together with Bondo...Easy.

 

[h2odesperado]

wow. I am in awe of what you're doing and so quickly too. Completely rebuilding the bottom of a boat. yeeesh. Thats a huge ride plate. Will that have any effects on handling?

 

[butti]

now i see what your doing:sneaky: what do you have in store for the top deck?:sneaky:

 

[Flash-FX]

It was time to make a actual part. The ride plate is a small enough piece that was built in a short time. Here again, standard tooling methods are used. Tooling
gelcoat, fiberglass matt, and a support base. Simple enough.
Another amazing thing about the Duratec primer is that it can be wet sanded and polished to a high gloss! Cool stuff. The same treatment will be given to the rest of the hull.
Sorry, there are a few pictures that got "lost" from my computer when some idiot took out the powerline up the block. A big crash.

The parts are all made with West Systems epoxy and vacuum bagged. It sounds
complicated but it really isn't. The final black finish is a epoxy/graphite gelcoat.

 

[Flash-FX]

wow. I am in awe of what you're doing and so quickly too. Completely rebuilding the bottom of a boat. yeeesh. Thats a huge ride plate. Will that have any effects on handling?

It took a way Loooooong time. And the ride plate mold is way longer than it needs to be. I trimmed the 2nd plate down to a "shorter than stock" length. I will test them soon.That's the beauty of making your own. They are only cheap fiberglass and you can hack away and find out what suits your riding conditions.

 

[Flash-FX]

now i see what your doing:sneaky: what do you have in store for the top deck?:sneaky:

A Top Deck?...perhaps in a "next chapter". But I need to dial this thing in first.

 

[Metal4130]

All I can say is WOW. Your craftsmanship is amazing. I've never seen anything so cool done to a ski. Your plug looks right on the money and I can't wait to see the final product! Just a question, what do you do for a living? Amazing!

 

[Mile9c1]

That's going to be a wild ride! But why not just buy a bottom hull from Waterdawg? Even if you had to wait 2 years for it, you'd have been on the water already :biggrin:

 

[Slug]

Can you make one out of carbon for me :biggrin: Your bottom hull with my top hull would be one awsome Fx1 :cool2: .