SX/SXi/SXi Pro How to build a 750sxi the right way

Location
WA
So, I've taken it out a few times and had a chance to compare it with my dads stock 08 sj that I usually ride. In short, the tubbies are awesome. I couldn't imagine trying to ride this thing without them. The steering/handle pole is great, and vastly superior to the kawi setup as it centers you on the ski a bit more and just plain doesn't feel awkward like the kawi setup does.

The hull rides great and With the tubbies I just don't see the point in ever selling this thing for an sj hull , in the end they both perform roughly the same, its just a matter of getting used to one hull or the other.


With that said, the sj 701 even in stock form does have significantly more low end punch, and the sj pump feels like it stays hooked up better then the 750 pump, the kawi hull could be a factor here tho, I'm not sure.


So, i guess im sort of at a crossroads that probably every 750 owner runs into at some point. Do i start dumping money into the kawai to get more low end, ride it as is and save up for an aftermarket hull and drivetrain (and keep the kawai as a backup ski), or do I swap in a 701 based engine and then I would always have the option of throwing the drive train into an aftermarket hull later. The latter option is starting to seem like the best way to go, however I was wondering what peoples thoughts were on modding the 750. What mods would be needed to get about the same amount of low end as a stock 701? Just a pipe?
 

socal750

Socal750
Location
beaumont CA
750s and Superjets are 2 different animals...pipe with a silencer and twin carbs some porting and bumped compression the 750 will be a rocketship....but with the same mods to a superjet will be more of a freeride ski not a dragster
 

socal750

Socal750
Location
beaumont CA
Did you ever find the low end you were looking for??? Man this ski came out looking good, my buddy was having low end drama with his ski and ended up switching to a big hub prop and it made a night and day difference.... Updates!!!


Sent from my iPhone using Tapatalk
 

N3vrSat1sfied

Military Member
Location
Fort Worth, TX
Did you re-enforce the nose? Also the front corners of the hood are very weak for pancaking rolls. See pic, these areas need some help.
 

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Location
WA
is there any more detailed pics of the carbon wrap on the hood and near the bucket ect?

I didn't reinforce the hood, although that would probably be a good idea. I only did carbon on the sides of the ski. The nose was "re-built" by the guys who painted it where they basically replaced a large section of the nose. I was told they just used fiberglass, which should be stronger than the stock smc crap. Also, before it was painted I layered in a bunch of thick (I can't remember the size) fiber glass all over the inside of the nose and handle pole area. I'm not sure how much weight this all added, I didn't notice a difference. It's held up pretty good!

I've decided I'm just going to mod the 750…I've already come this far might as well keep going. So, I'm starting with a head kit from optima and seeing if that makes any difference in low end. I'm replacing some of the stock tubing as well next weekend, I'll keep the updates coming…
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I didn't reinforce the hood, although that would probably be a good idea. I only did carbon on the sides of the ski. The nose was "re-built" by the guys who painted it where they basically replaced a large section of the nose. I was told they just used fiberglass, which should be stronger than the stock smc crap. Also, before it was painted I layered in a bunch of thick (I can't remember the size) fiber glass all over the inside of the nose and handle pole area. I'm not sure how much weight this all added, I didn't notice a difference. It's held up pretty good!

I've decided I'm just going to mod the 750…I've already come this far might as well keep going. So, I'm starting with a head kit from optima and seeing if that makes any difference in low end. I'm replacing some of the stock tubing as well next weekend, I'll keep the updates coming…
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Yeah it looks like your into that pretty deep!
 
Location
WA
Thanks guys. I've been busy with work, but I've got a green ADA head kit coming here soon. I'll post install picks as soon as I have time to work on the ski.
 
Thanks guys. I've been busy with work, but I've got a green ADA head kit coming here soon. I'll post install picks as soon as I have time to work on the ski.
You get your head yet? I ordered a green one about a month ago and I'm still waiting. Mike said there was a pretty long wait on green.
 
Location
WA
Just received mine today actually! I had to wait about 1 month or so, totally worth the wait it's too cold to ride here anyways. I just ended up getting the 91 octane domes because I don't want to have to run race gas. Anyways, I might get some time this weekend to install it, gotta get my ignition swapped out first though, hopefully that fixes this weird electrical issue I've been having. One thing at a time. For the head, anything specific I should watch out for when swapping everything out? I'm assuming it's pretty straight forward, just replace everything then torque everything down to spec I guess?
 
LoCash that's a great looking 750. I like the pole too, there aren't too many RRPs on these old skis.

A few things about low end on 750s. The cylinder you have is the worst for low end. Ideally what you'd want would be an original 750sx cylinder. Those things had the lowest port timing an have the greatest low end potential. Next would be the small pin dual carb / xir type cylinders. SXR 800 cylinders are roughly similar to those. And lastly the 96 and up / big pin cylinders have the highest port timing. They are racing cylinders.

I would get a 750sx or lime green head / small pin 750 cylinder and have it freestyle ported. 750 cylinders are insanely cheap. Then have a reputable place freestyle port it. I have a 800 superstock cylinder in my ski ported by a guru who used to do work for Kawasaki back in the day. Its an awesome cylinder and my ski is set up as an old racer. My brother has a pro but all set up for freestyle. Z Force racing freestyle ported 800, factory pipe, dual mikunis, Advent, and those same tubbies. For a 750 it has tons of low end and a totally different character from my ski. He can get very good air off the small wakes we have on our lake.

If you have the cash I would 1000% recommend the freestyle port 750 cylinder. I was told by Tim Z at Z Force that the extra displacement to an 800 wouldn't actually give you that much low end, by comparison to going to a well ported 750sx cylinder.

Hope that helps! I've been there and done that on these 750s. For a 2 cylinder engine I'd rather have the pro I have now over a sxr. With the 3DR hull mods it feels friendly and nimble like a 750 but rails like a sxr. My brother's ski is really fun, considering it isn't a yamaha and has the smaller Kawasaki pump. I'm pretty sure his ski now has more usable low end over a friends FX1 with a factory pipe and 144mm pump. His engine is tired and the throttle response isn't as great. One of these skis well set up can hang its own!
 
I'm not going to lie, the first thing I noticed about the ski my first time out was just how crappy it handled compared to the SJ I normally ride. The ski felt extremely unstable in corners and tended to tip over when I shifted my weight even a tiny bit to much to one side. When comparing it to the SJ, the SJ feels like riding a square and the 750 feels like riding a narrow pencil (as many others have pointed out). However, this also made it a blast to ride especially when running at full throttle and trying hit sharp corners, and then flying off and skidding across the water.
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LOL this cracks me up. Yea this is the difference between Kawasaki skis and Yamaha SJs. The SJs steer better but the Kawis love to lean and carve. They "steer" better in the vertical plane, if you can imagine that. You can lean them right over in the turns bars to the water.
 
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