Other What skis for full drivetrain swap?

Balduccimoto

Balduccimoto

Location
NYC/Long Island
Just what title says, what skis can I buy on craigslist and swap full engine, carbs, electronics etc right into my superjet? I'd like to go back to stock. I wish to ride rhe rest of the season without aftermarket :):):):) blowing up. Might as well buy used since new blows up anyway.
 
97superjet

97superjet

Location
Minnesota
Wouldn't you need to just buy another SJ to swap back? Also don't you have your stock parts anymore? Also curious whats blowing up or not working with your aftermarket setup?
 
lanmine657

lanmine657

Location
fortcollins
My 95 sj has just about every bolt on am part you can get, basically a limited setup, the motor has never been touchd, still on its original top end and crank, boats shouldn't just blow up for no reason
 
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OCD Solutions

OCD Solutions

Original, Clean and Dependable Solutions
Location
Rentz, GA
mthomps said:
Can't beat the reliability of an OEM yamaha driveline though!
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I have never owned a stock yamaha yet and never had an issue that wasn't caused by my own neglect or ignorance. My current ski's were built up from bare hulls and have been mostly trouble free for over 3 seasons. My wife's piped and ported 760 has been the most reliable ski I have ever owned. My Matrix has been as well except for a rubbed cable that was always draining my battery. The rest is routine maintenance from riding salt like a failed stator, midshaft and steering cable.Engines haven't skipped a beat since being built and tuned.

Not knowing the full story and not trying to be hard on you but the problem is most likely you or your current mechanic. Unless you have learned something new or switched mechanics, what's to say that the same mistakes won't be made during the swap and you won't end up in the exact same place? I know it sounds harsh but I my intent is not to bash you but rather to get you to just take a deep breath and look at this from another angle. Ask for help, do some more research and don't give up on what you currently have.

There is always some missing piece of the knowledge puzzle and a single ski in all our pasts that hands us our ass. Mine was a 98 GSXL that I struggled with for two years after a major engine upgrade. I owe all my current knowledge to that single build. It taught me more about 2 strokes than all the other ski's I have owned combined and I wouldn't take a second of it back. I wanted to give up at times but I suffered thru and kept learning and that experience has made me a better mechanic.

After all, if everything worked right the first time, what would we have learned?

Edit: I read back thru your threads and read about your engine troubles and I feel your pain. You have a real head scratcher where you should have a kickass and reliable ski. We had similar issues but were running way smaller domes to achieve the same compression numbers you are posting. We ran 32 cc domes and backed off to 34 cc domes to keep from eating pistons.
 
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yurkanip

yurkanip

Location
Great Pacific Northwest
lanmine657 said:
My 95 sj has just about every bolt on am part you can get, basically a limited setup, the motor has never been touchd, still on its original top end and crank, boats shouldn't just blow up for no reason
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Agree, Although I wanted more power and went with a jetmaniac 718 which is an amazing motor. My original SJ650 motor went 18 years, with out the top end/case even being cracked. (paint was still unchipped on every cylinder bolt).
 
Vumad

Vumad

Super Hero, with a cape!
Location
St. Pete, FL
mthomps said:
Can't beat the reliability of an OEM yamaha driveline though!
Click to expand...

Because it is tame. Anything detuned to be reliable will be reliable. Stock Superjet turns 6500 RPM. Limited superjet turns 7000+ RPM.

I try to explain to all of my friends who bash on seadoo all of the time. They come aftermarket from the factory. Yamaha 700 is 73 horsepower and seadoo 720 is 85 horsepower (3% displacement, 14%hp). The Yamaha 760 is 90 horsepower and the seadoo 787 is 110 horsepower (3% displacement, 18% HP). Those ratios are rough as I know a 760 isn't exactly 760cc.

Anyway, my point is, the only reason stock yamaha is reliable is because they turn back the power to make it that way. I don't think a single person on this forum would contest that the superjet exhaust is among the worst ever made. I mean, people take the pipe off the 650sx and put it on the 701 superjet, it's just that bad.

Increases in performance result in decreases in reliability. There is nothing more to discuss on the topic. If your 900s are too costly to maintain, and too tweeked to keep running, go back to a stock motor limited setup.
 
King Kang

King Kang

Never enough tray time...
Location
Cary, NC
I feel like this tread might be getting off topic with the debate between tuned vs stock reliability. As SJ 650 owner, I'm interested in knowing the answers to the original question- which motors are the easiest to swap into a SJ, and which ones are most challenging.

Blasters seem pretty hard to find, but VXRs like these are a dime a dozen.

http://raleigh.craigslist.org/boa/3964420140.html
 
TheBuzzard

TheBuzzard

Location
the jetski grave yard
yea, i love finding those vxr pro or wr3 701 models for dirt cheap. the motor, exhaust, carb, electronics all comes out in about 10 minutes and in one piece and drops right in a superjet hull. too bad they are the 61x single carb models, but they usually look like brand new and need very little cleaning.
 
OCD Solutions

OCD Solutions

Original, Clean and Dependable Solutions
Location
Rentz, GA
There are many detailed threads with this information already, even down to what parts can be used and where. If there isn't one in the tech section already, we should definately get at least one added.
 
Vumad

Vumad

Super Hero, with a cape!
Location
St. Pete, FL
Any 650, 701 or 760 will bolt right in. The 144 pumps swap over. The differences are in the shafts. The water boxes do not move over b/t models unless you are going to rig something. The 1100 and 1200 motors can be used with a lot of work.
 
Vumad

Vumad

Super Hero, with a cape!
Location
St. Pete, FL
Vumad said:
Any 650, 701 or 760 will bolt right in. The 144 pumps swap over. The differences are in the shafts. The water boxes do not move over b/t models unless you are going to rig something. The 1100 and 1200 motors can be used with a lot of work.
Click to expand...

The big 760 exhausts (like gp1200) do not fit easily, lots of extra work involved in these pipes. I believe any 701 pipe will bolt onto a 760 cylinder. However, I remember reading a while back chuckie (supertune xscream) that the 760s like big expansion chambers and don't perform to their potential with the smaller 701 pipes.
 
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