Freestyle 550 750 freestyle conversion

[chip H]

I recently bought a beat up 550 and a 750 xi sport donor ski on craigslist. The 550 engine was in pieces, but now I have a ton of 550 aftermarkets from the ski.. all of which must sell. I only wanted the 550 for the hull itself. My goal is to build a budget freestyle ski and I am looking to spend no more than about $1500 on the whole project. The end goal here is a backflip in the surf, or at least a barrel roll. I just want a cheap ski to rip on.

 

[kwakhead]

I want some 550 performance parts for my js550 racing build. Lol just finished my conversion, ON TO THE NEXT PROJECT! lol something for me to do till summer here in Michigan.

 

[kwakhead]

And my 750 sxi racing ski if u have some parts for those.

 

[fastgtfairlane]

its gonna take a whole lot more than 1500 to build what you want... just sayin

 

[chip H]

@kwakhead I've got a west coast pipe and water box if you want them. Could probably get some small parts out of my xi sport (donor ski) but those aren't exactly top of the line parts haha. Could also pull some parts out of the 550 engine..but most of it is shot. Send me a list of what you want and ill let you know. By the way awesome 550 750 conversion. your thread is extremely helpful.

 

[chip H]

Ive been stripping paint on this thing for about two weeks using a heat gun and a stripping knife. I know people say this is not the way to go, but truth is theyre wrong. Ive done the whole ski like this and its quicker and beats gumming up your orbital sander with paint gunk. Anyway, here is the ski as I bought it...
This weekend I finished stripping the paint and then cut the siderails in the tray; giving myself a partial flat deck which will give me more room to mount my footstraps. After that I sanded the whole ski.

 

[chip H]

Wanting to buy a new 550 pump, nozzle (for trim), and impeller. Let me know if you are selling. Also if im running a 750 engine what pitch prop should i go with?

 

[chip H]

But more importantly.. if I am planning on installing a trim system how in the world do you install the trim cable? Am I going to have to cut the top deck off in order to route it from the bulkhead to the pump cavity?

 

[Midlake Crisis]

But more importantly.. if I am planning on installing a trim system how in the world do you install the trim cable? Am I going to have to cut the top deck off in order to route it from the bulkhead to the pump cavity?

I haven't done this, but here is a technique used to install a scupper that seems like it might work:
http://www.pwctoday.com/showthread.php?t=123251

 

[kwakhead]

Don't mess with tuning the 550 pump in. You will have to find a 21 straight prop,and u will have a hell of a time finding one lok. Do what I did, I cut the bottom out of a 650sx and did a pump conversion. If you cut the entire bottom out, up past the motor mounts, you could just bolt everything from the 750 straight in, no need for conversion plates, adaptors, longer couplings, ext. Just do or research on fiberglassing. And if you want to back flip or 550 like I have, you want the 650 pump, not the 550 pump. The 650 pump is SO much bigger in comparison. Take my advice, cut the bottom out of a 650 and glass it into a 550. And use EPOXY resin. Normal polyester doesn't stick. I learned the hard way.

 

[kwakhead]

uote="chip H, post: 1589339, member: 17307"]But more importantly.. if I am planning on installing a trim system how in the world do you install the trim cable? Am I going to have to cut the top deck off in order to route it from the bulkhead to the pump cavity?[/quote]
Ur probably not gonna be able to find a trim for a 550 pump. Do a 650 pump conversion. Cut the entire bottom out of a 650sx. I've got one laying around, I'll cut the bottom out, send u the driveshaft, bulkhead, and D's support. I will cut it out past the motor mounts so u can just bolt the 750 in without having to purchase conversion plate and couplings. Much cheaper, and better way to go. Trust me. We can negotiate the price, it will be just the cost of labor and shipping, but trust me u want the 659sx pump and drive line, the driveshaft is 1/3 the weight of the 550 driveshaft for more speed and power, bigger pump for more speed and power, and u don't have to worry about busting your 550 pump overtime. All the guys running 550 pumps on their conversion skis have to constantly keep an eye on their pump. Trust me, its way worth the effort! Throw some freestyle tubbies on too and rocker the nose!

 

[kwakhead]

And if your building a freestyle ski, strictly freestyle and free ride. Shorten it at least 5in. With the 659 drive line u can shorten it even more as well. Its cheaper, better, more powerful, faster, and just a better decision. If you do the fiberglassing right, its a blast.

 

[kwakhead]

650 drive line. Not 659 sorry

 

[chip H]

@kwakhead What if I were to cut the bottom out of my 750xi sport instead? Keep in mind its a sit down ski, but I would have a bigger pump and everything would fit the engine I'm running because that came out of there too. Id rather not spend the money if I already have the resources...problem is I don't know if I actually have the resources haha.

 

[Brian_216]

Don't mess with tuning the 550 pump in. You will have to find a 21 straight prop,and u will have a hell of a time finding one lok. Do what I did, I cut the bottom out of a 650sx and did a pump conversion. If you cut the entire bottom out, up past the motor mounts, you could just bolt everything from the 750 straight in, no need for conversion plates, adaptors, longer couplings, ext. Just do or research on fiberglassing. And if you want to back flip or 550 like I have, you want the 650 pump, not the 550 pump. The 650 pump is SO much bigger in comparison. Take my advice, cut the bottom out of a 650 and glass it into a 550. And use EPOXY resin. Normal polyester doesn't stick. I learned the hard way.

Id like to see this backflip. Got any videos?

Sent from my SAMSUNG-SGH-I337 using Tapatalk

 

[kswiatk]

Nice job so far, you should post some more info on what you are planning on running or what you already have. Engine? pipe? anything really would get you more response.
Since your looking for a budget build you should hold off on most body work, resin gets expensive. Even in kwakhead's build he spent 1500 on glass material alone.

You should also realize the limitations, if any, of other parts affecting others. I.E. if your running a big pin motor(bad bottom end) with stock carbs, head, pipe, porting pumping up to a 650 pump wont get you the performance you are looking for.
IMO it is better to get the engine upgraded and reworked before changing any of the pump sizes or larger expensive projects. This is especially true if your engine already has limitations on it, such as the port timing on the big pin 750. You aren't going to get the freestyle experience you want with the limitations of some of the parts. Especially if its never been rebuilt...

Also, why not just save the 1500 on glass and get a born and bred freestyle machine, the superjet.
Hate to rain on the parade, I was raised to be a pessimist.

And I really want to ride this thing so hurry up and finish it!
See ya this weekend
-kswiatk

 

[kwakhead]

Nice job so far, you should post some more info on what you are planning on running or what you already have. Engine? pipe? anything really would get you more response.
Since your looking for a budget build you should hold off on most body work, resin gets expensive. Even in kwakhead's build he spent 1500 on glass material alone.

You should also realize the limitations, if any, of other parts affecting others. I.E. if your running a big pin motor(bad bottom end) with stock carbs, head, pipe, porting pumping up to a 650 pump wont get you the performance you are looking for.
IMO it is better to get the engine upgraded and reworked before changing any of the pump sizes or larger expensive projects. This is especially true if your engine already has limitations on it, such as the port timing on the big pin 750. You aren't going to get the freestyle experience you want with the limitations of some of the parts. Especially if its never been rebuilt...

Also, why not just save the 1500 on glass and get a born and bred freestyle machine, the superjet.
Hate to rain on the parade, I was raised to be a pessimist.

And I really want to ride this thing so hurry up and finish it!
See ya this weekend
-kswiatk

Lol born and bred freestyle ski? Superjet? I don't think so, its heavy. But not as heavy as a 750sxi, 800sxr, 650sx. The 550 is lighter. He won't really get what he's looking for out of a $1500 superjet, it would be a crappy to decent superjet for only $1500. IMO stick with the build. You will be surprised in the end. I'm telling ya, I've been there, done that. Do the 650 pump conversion. I'll cut the bottom out of a 650 I got laying around and send it to you.

 

[kwakhead]

I've had superjets, and I've always liked them for freestyle and free ride, great all around ski. But when you shorten the 550 hull, put a bigger pump and engine in, and freestyle tubbies, and if I were you get an aluminum handle pole, the 550 is a tells of a lot lighter and more nimble. Check out my build for ideas, and that guy who did the 550sx hull modernization build, I got all my ideas from him lol

 

[kswiatk]

Lol born and bred freestyle ski? Superjet? I don't think so, its heavy. But not as heavy as a 750sxi, 800sxr, 650sx. The 550 is lighter. He won't really get what he's looking for out of a $1500 superjet, it would be a crappy to decent superjet for only $1500. IMO stick with the build. You will be surprised in the end. I'm telling ya, I've been there, done that. Do the 650 pump conversion. I'll cut the bottom out of a 650 I got laying around and send it to you.

Well it depends on what your riding style is. If your on a lake then a light 550 with a small pin or a yami engine with good bottom end is gonna be a lot more fun than a superjet(if he sold the 550, 2300+ would get him a decent sj), but if your planing to do free riding or surf(even lake Michigan) a sj would handle much better than the 550.
I know he is going to do a lot of surf riding so that's what i was referring to.
If he was doing a mainly lakes then 550/650 pump swap all the way.

I dont like to see it this way, so please tell me im wrong lol.
Now back to the thread.

 

[chip H]

Built a wakeboard winch and rode a little bit with @kswiatk but now im back to work on the jet ski. Still not sure what im going to do in terms of the pump...id take the 650 pump over a 550 any day....money is the only thing im concerned about. Glassing in a 650 pump seems rather risky...

Anyway, im taking my ski in to see my friend who owns an auto body and repair shop. Gonna get a hands on experience learning how to glass.. there are a few holes that need epoxy and the whole back of the ski needs to be glassed over after cutting the tray sides to make a partial flat deck. Maybe if I can get a feel for how hard glassing is I could make a decision on whether on not to do the 650 pump conversion.