Another dang FX1 pump thread......

[special fx]

Ok so you're probably tired of reading about FX1 pump upgrades, but I'm going to add to the mix anyway. I think it's a no brainer that the FX1 is the shiznit when it comes to ocean riding (and any other riding in my book), but we all whine about the pump cavitating. There are many differing opinions/options for squeezing a 144mm pump into the FX and they seem to run the gammit from the apex of the spectrum (FlashFX 's thread) to the some pretty shoddy silicone, bubblegum and booger type mods (not gonna point any fingers here).


I've lurked on various threads and projects and decided on a path that I feel is right for how I ride. One mod I found just too intriguing not to pursue is the Kawasaki 650 pump. It's 140mm and handles Kawi power all the way up to the 1100, so it should handle my little 701.

I found this thread on PWC with a couple of pics of a 750 pump in an FX and it seemed pretty clean: http://www.pwctoday.com/showthread.php?t=65980&highlight=kawasaki+fx1


I like this, but wanted to use a 650 pump. I have a couple of spare FX1 hulls, so I bought some used 650 junk and started playing. The pump will fit into the hull with a little grinding on the pump shoe and hull. The stock front pump mounting area needs to be ground down as well to get a level mounting surface ( the FX has a stepped mounting and the 650 is level)...not a biggie!

I got it fitting so that the FX scoop grate will even bolt right up to the stock 650 mounting hole.

 

[special fx]

In the thread where the 750 pump was mounted, they used an aluminum plate to convert from the yamaha bulkhead bearing mount to the kawasaki bulkhead bearing. This seemed pretty straight forward and I started down this path, I even marked up the part on a piece of billit and was going to start machining when I had a lucid moment. When looking at the Yami and Kawi bearing housings it became apparent that I didn't need a conversion plate. What I needed was to find bearings that fit the yami housing but had the inner diameter to fit the kawi shaft. That would allow use of the FX bulkhead housing, but let me run the kawi shaft.

Alas......I could not find any bearings with these specs:banghead: , so I stared at it some more and decided the best route was to take a kawi bulkhead housing and remove the core and machine it fit into the FX housing. This lets me use a stock FX housing/mounting and stock Kawi bearings and seals.....thus making both the FX bulkhead happy and the Kawi shaft happy....:Banane01:

Here's the Kawasaki bearing housing core after maching, and then pressed into the Yamaha housing:

 

[special fx]

Here's the housing with shaft in the hull for a trial fit. It seems to fit perfect without any hassles. I machined the tail end of the kawi part so it would fit into the FX bulkhead without grinding any glass.

The internal kawi piece is positioned in the FX housing to give the exact same distance between the coupler and the bulkhead as the stock FX shaft, so engine coupler alignment should not be an issue.

 

[special fx]

The next step is to get some new parts. I used some old junk I had laying around just to figure this out. The end result should allow me to replace bearings, seals and even the pump itself without having to re-machine stuff, making basic maintenance a lot easier.

I'll be lurking threads on 650 props to figure out the best prop to go with. I have a 15 degree Skat that came with the pump I bought and it's in good shape. That may be the prop I use until I find something better.

The one kinda cool think about this mod is the cost. Here's where I sit so far:

650 pump in very good condition w/15 deg Skat prop.......$49.00 on ebay
900 sxi driveshaft in near perfect condition.......................$17.95 on ebay
Kawasaki bearing housing................................................$7.50 on ebay
Hopefully killer hookup compared to stock FX tiny pump.........priceless!

I also bought a tilt nozzle for 50 bux that I'll play with to see if I can make that work.

 

[WFO Speedracer]

looks good so far keep up the good work

 

[Flash-FX]

The $1,000,000.00 question.....Is going to make Daytona? :skull2:

 

[special fx]

How 'bout.............noooooooooo

 

[Mile9c1]

It's 140mm and handles Kawi power all the way up to the 1100, so it should handle my little 701.

Actually they only used it up to 900cc which was 100hp. Nontheless, it looks like a NICE upgrade for the FX-1 :biggthumpup:

 

[WAB]

Cool idea
Is that 900 zxi driveshaft splined at both ends and is the right length already??

 

[joe b]

Ahhhhh... The chief is in the house:woot: Glad to see you've finished the road burner and made it this far without:skull2: Hopefully next season I won't be ridding by myself half the time:cool2:

 

[special fx]

The 900 zxi driveshaft looks to be the exact length for the FX. It has splines on the prop end that mate to teh 650 prop and larger threads (than the 650) at the coupler end so the FX coupler will thread right on. It's like it was made for it.

Here's a pic of the FX driveline next to the Kawi for comparison. They both have a length of 18 1/4" from coupler to pump. I though I'd post all this crap to help someone else who may want to attempt this. I bought several driveshafts to figure out what would work. Anybody need a 650 or 750 driveshaft:banghead:

 

[adet16v]

looks good so far. What steering cable will you be using? Are you going to be using the kawi couplers now as well?

 

[oxnard111]

Very interesting thread. This is the first time I have heard of this type of pump conversion. Good luck. Looks good so far. I have an old 650 prop in the garage. I think its a Skat, and it only has the number "5" printed on the side. I'll take a better look when I get home. If that is something you might need let me know.

 

[douglee25]

looks good so far. What steering cable will you be using? Are you going to be using the kawi couplers now as well?

Damn! I haven't seen you on here in a while :biggthumpup: Welcome back! Daytona Adet?

Doug

 

[special fx]

As far as steering cable, if the 650 pump is used "as-is" you have an issue with cable length (too long). I'm playing with various parts trying to come up with a solution that requires the least amount of mods and it appears that when used with a 750 tilt nozzle the length is perfect and you get trim as an added bonus! :cheer:

 

[kx454]

what 750 driveshaft you have?? sxi pro, sx ?

 

[special fx]

Someone asked about couplers........

I was going to use stock Yamaha couplers. The 900 driveshaft is the same thread as the stock Yamaha driveshaft, so the stock Yami coupler will thread right on.

However, Just for Sh*ts and giggles, I chucked up a Yamaha half shaft in the lathe and threaded a stock Yami coupler on it to check it out and Damn...was it out of round! I figured...OK, that one is junk and I must have damaged it over the years. So, I put another stock coupler on and checked it out and it was junk too. I went through 3 couplers and all were way the hell off (and yes the shaft is straight). I now know why I was detroying shaft splines!:banghead: The worst one was about .240" out and the best was about .125" out.......junk!!!

I'm going to use a set of billet Yamaha couplers that I just picked up off evil-bay. Hopefully they will be a little more precise? I wonder how many stock couplers are this bad, it appears they were drilled off center and crooked.

KX454.......The 750 shaft I have is listed as a 750 sx/sxi. If you need it, let me know? Prolly like 20 bux??

 

[adet16v]

As far as steering cable, if the 650 pump is used "as-is" you have an issue with cable length (too long). I'm playing with various parts trying to come up with a solution that requires the least amount of mods and it appears that when used with a 750 tilt nozzle the length is perfect and you get trim as an added bonus! :cheer:

yeah i figured there would be an issue with the cable and 650 steering nozzle, thats awesome if the 750 nozzle works!

 

[adet16v]

update? completed? in the water? i have a 650 pump at home... im waitin to see how this turns out:cool2:

 

[special fx]

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.