1990 Square nose superjet build for freestyle

Location
Wisconsin
OK I think everyone has the idea that I put it in and I really like it. I didn't and I don't care either way lol.

The good news is that the 62T has the original choke system on it and that will be going in the ski.


Interesting. I will look into that. I originally wanted a side exhaust but I heard mixed reviews about them and just to keep the original outlet. I much prefer the sound and simplicity of a side exhaust.
Go ride a 650sx once with side exhaust, it is terrible.
 
I do tail stands all the time on my 750sx and SJ....its a trick I love...what's the issue with rear exhaust?
No issue really. Just things to consider as I'm building it over the winter. I want to build it up before the season starts. I'm getting ideas on what to do to make sure I don't have to modify too much during the season and get more tray time.
 

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
I do tail stands all the time on my 750sx and SJ....its a trick I love...what's the issue with rear exhaust?
I don't have any issue with rear exhaust and everything I have has been converted to rear exhaust if it didn't have it already, this is a question you need to address to Kevbo.
 
Location
dfw
You guys never get the nose high enough for the exhaust to vent the pump. Its when the ski is about to fall backwards that the rear exhaust will vent the pump. Then all you get is the rev limiter and the ski falls. Then the pump reprimes and the ski shoots out of the water. I never had problems until I got better at tail stands, especially now that I can go backwards. Adding a side dump is so easy you don't even need to cur any hoses.
 
Location
detroit
You guys never get the nose high enough for the exhaust to vent the pump. Its when the ski is about to fall backwards that the rear exhaust will vent the pump. Then all you get is the rev limiter and the ski falls. Then the pump reprimes and the ski shoots out of the water. I never had problems until I got better at tail stands, especially now that I can go backwards. Adding a side dump is so easy you don't even need to cur any hoses.
Oh you mean at the right angle you suck exhaust gases into the pump intake and then you lose thrust. I have had that happen a few times, I have just learned to position differently.

......by going backwards do you mean you get the nose past the 12 o-clock position during a tail stand? or do do you mean something else?

any photos of this side dump setup?
 
Location
dfw
I mean I have to pull on the footholds and push up on the bars to keep it from falling on top of me. It cant be done continuously unless you are wearing a lot of floatation. You have to go back to the neutral point and stretch your body back out. For the exhaust, I placed the 90 degree dump against the bulkhead and connected the hose. Then I pulled out the heavy stainless tube.
 
Ok so I won’t change the exhaust exit location. That’s settled.

I’m about to start tearing into the superjet and wave raider to remove the motors. One question I had, what exhaust bracket solution do you know of for the 62t to fit inside the superjet with a superjet exhaust? I have an 08+exhaust I got from someone on marketplace but the brackets still won’t line up on top of the head. Do I just make another bracket from scratch or is there an easier solution? I was thinking about doing a b pipe down the line but wanted to run the ski stock and see the differences as I do them. That way I can know more about what mod changes what characteristic while riding.

Bonus pic of me ripping my JetSurf. If you get a chance to ride one of those, don’t pass it up! They are a blast!IMG_4999.jpegIMG_5001.jpegIMG_5002.jpegIMG_5003.jpegIMG_5004.jpegIMG_5477.jpeg
 

be_lain

Currently sending it
Location
Oregon
You’ll need a 61x head if you want the pipe to mount up properly. The raider manifold outlets to the back of the ski so it won’t work in the superjet. Also you’ll have to thread some m8 helicoils into the 62t cylinder, the bolts are m10 but the superjet exhaust manifold only accepts m8
 
Location
dfw
Higher port 62t cylinders need a lower pitched impeller for best response. The stock SJ exhaust has no tuning to speak of. 62t cyls will go faster than a 61x will once a good pipe is installed.
 
You’ll need a 61x head if you want the pipe to mount up properly. The raider manifold outlets to the back of the ski so it won’t work in the superjet. Also you’ll have to thread some m8 helicoils into the 62t cylinder, the bolts are m10 but the superjet exhaust manifold only accepts m8
Will the 61x head produce as much power as the 62t or should I look into aftermarket? Not sure about the dome sizes or if I should even worry about it at all. Thanks for the advice!
Higher port 62t cylinders need a lower pitched impeller for best response. The stock SJ exhaust has no tuning to speak of. 62t cyls will go faster than a 61x will once a good pipe is installed.
I was thinking of the 9/15 impeller to start off with. Then put an aftermarket pipe on later and see how it wakes up.
 
Location
dfw
Higher ports will make more power when the pipe is working and make less at lower rpm. On a ski it can take some careful pump load tuning before a high port will get on the pipe quick enough. Low port 61x cyls make more power below the pipe so their owners have a much easier time getting good response. With the stock exhaust there is no power surge but it will be more responsive with a light pump load. I would bore the nozzle, that is always good for more thrust.
 
Higher ports will make more power when the pipe is working and make less at lower rpm. On a ski it can take some careful pump load tuning before a high port will get on the pipe quick enough. Low port 61x cyls make more power below the pipe so their owners have a much easier time getting good response. With the stock exhaust there is no power surge but it will be more responsive with a light pump load. I would bore the nozzle, that is always good for more thrust.
Ok I just bought a 61x head for it
Curious. What lake was the Jetsurf pic taken on ?
It’s on Belleville lake in Michigan.
 
Location
detroit
I almost bought a house on that lake, but I've heard that lake isn't the cleanest...gets very green and isn't good for the sinuses if like to inhale water.

What are your thoughts? Overblown?
 
I almost bought a house on that lake, but I've heard that lake isn't the cleanest...gets very green and isn't good for the sinuses if like to inhale water.

What are your thoughts? Overblown?
Lots of algae growth causes the lake to be dirty. Have to keep skis and boats out of the water or it’s terrible on the bottom of them. Haven’t experienced anything in my body from the lake though. But I also don’t inhale water that much. Maybe after I get this ski going I can review that part for you as I plan to be learning all next summer.

The lake itself is awesome though. Lots of room and if you live on it you can go out when it’s not busy. I’ve enjoyed living here for sure.
 

wydopen

onthepipe
Lots of algae growth causes the lake to be dirty. Have to keep skis and boats out of the water or it’s terrible on the bottom of them. Haven’t experienced anything in my body from the lake though. But I also don’t inhale water that much. Maybe after I get this ski going I can review that part for you as I plan to be learning all next summer.

The lake itself is awesome though. Lots of room and if you live on it you can go out when it’s not busy. I’ve enjoyed living here for sure.

If you have the $ for a pipe I wouldn't waste time running the stocker.
 
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