Small pin to big pin

[nwcitizen]

Okay I’m a kawi rookie. I acquired a 94 750sx single carb ski to rebuild for my 11yr old son. It’s a bit of a basket case as it was used to diagnose another ski last summer. Well I ended up scoring a 750zxi to rob the big pin out of that is healthy. My question is, do I need to source a sxi ebox or will the single carb sx ebox work fine? Or piece together an ebox between the 2 I have? Also, the ski has an intake grate, extended ride plate and a prop that i need to figure out the pitch on once I get into it. I’m purchasing hull extensions and installing my spare round nose pole on it. Are tubbies worth it on this ski? I came from 550, 650sx days when I was a kid, then into sn and rn superjets and blasters. I have never ridden one of these hulls but read that they basically suck lol. But I’m working on a sub 2k budget ski for an 11 yr old kid so he stops taking my ski so much and we can shred together. Any cheap advice is appreciated.

 

[kevbo]

The 750sx CDI box needs stators that have windings on every pole. The ZXI CDI uses the battery so its stator has two poles left unwound. The 750sx is an inch narrower than the 650sx or Superjet, it also has more deadrise so it is easier to lean over. The old 750 likes to turn on edge where the Superjet turns flat. At high speeds, the 750s deeper keel makes the ski less stable in roll. I would leave the tubbies off unless you are racing. They can work great or they may create an annoying chine walk. My suggestion is to fix everything and make it as reliable as possible. I'm sure it needs some maintenance. Modify things as desired after that.

 

[nwcitizen]

The 750sx CDI box needs stators that have windings on every pole. The ZXI CDI uses the battery so its stator has two poles left unwound. The 750sx is an inch narrower than the 650sx or Superjet, it also has more deadrise so it is easier to lean over. The old 750 likes to turn on edge where the Superjet turns flat. At high speeds, the 750s deeper keel makes the ski less stable in roll. I would leave the tubbies off unless you are racing. They can work great or they may create an annoying chine walk. My suggestion is to fix everything and make it as reliable as possible. I'm sure it needs some maintenance. Modify things as desired after that.

So am I able to swap stators to run the sx ebox?

 

[nwcitizen]

The 750sx CDI box needs stators that have windings on every pole. The ZXI CDI uses the battery so its stator has two poles left unwound. The 750sx is an inch narrower than the 650sx or Superjet, it also has more deadrise so it is easier to lean over. The old 750 likes to turn on edge where the Superjet turns flat. At high speeds, the 750s deeper keel makes the ski less stable in roll. I would leave the tubbies off unless you are racing. They can work great or they may create an annoying chine walk. My suggestion is to fix everything and make it as reliable as possible. I'm sure it needs some maintenance. Modify things as desired after that.

And thank you for the info, we mostly just rec ride. We race mx year round and skis are for free time. There’s only 2 local jet ski races here. I prefer surf but my son isn’t ready for that yet

 

[WFO Speedracer]

Yes you can swap stators and run the 750SX electronics

 

[E350]

. . . The 750sx is an inch narrower than the 650sx or Superjet, it also has more deadrise so it is easier to lean over. The old 750 likes to turn on edge where the Superjet turns flat. At high speeds, the 750s deeper keel makes the ski less stable in roll. I would leave the tubbies off unless you are racing. They can work great or they may create an annoying chine walk.

@kevbo what is deadrise?
Thank you for your hull descriptions/comparisons. I am very interested in learning about hull design, before I make any hull modifications.

 

[kevbo]

That is the angle from the keel to the chine. Standups are generally flat or else they become effectively more narrow at high speeds. Get a 750sx over 50mph and you'll know how it feels.