Super Jet *Carnage update w/ pics!*There's a first time for everything..Like a motor blowing up

[Roseand]

Well I was riding today, first time out with my new plug wires! Had to put replace them cuz I couldn't cut back the old ones any further. Last time I was out, my ski would lose a little bottom end and clear up on the top end, just like it does when my wires start breaking down, then eventually the connection gets so bad it just limps back home. So today, it was running pretty good, just a little delay on the bottom end and it would clear out on the top end. Like a slight loss in bottom end, not much at all! So I took it to the pier, checked the plugs, and the rear plug was all gunked up. (it was to the point where it was feeling like it was only running on one cylinder). Put in a new plug, rode it for about 20 seconds and it started doing the same thing, to the point where it has like no power when holding it wide open. I was going about 5 mph and pretty much in "limp mode" and I felt a clunk and when I went to hit the starter, the starter would just click. It was locked up.. Luckily I was 50 feet from the pier.. Pulled out the plugs, saw metal shards in the rear cylinder..Yeah, I was heartbroken when I saw that :sad2:
It's a 1995 superjet 61x,original motor, only mods are a b pipe(previous owner installed it), a scoop grate, and a hooker prop 9/15, and a cdi with rev limiter set at 7750 RPM. . I've been running it all season with no big trouble till now.. It's my first stand up and season riding..

I barely rode it for 30 minutes before this happened..

*update* new pics!!


Honestly, the cylinders aren't in bad shape at all! The cylinder that the piston skirt broke didn't really even get scored.
Well I'd say my crank is pretty much shot LOL. That thing must have gotten pretty dang hot!! Melted it right off..

 

[4SeasonsPower]

That sucks, we've all been in your shoes once or twice. Perfect chance to upgrade to a Jetmaniac set-up. Turn those Lemons into lemonade.

 

[Roseand]

That sucks, we've all been in your shoes once or twice. Perfect chance to upgrade to a Jetmaniac set-up. Turn those Lemons into lemonade.

Not with my budget unfortunately ..
I'm surprised, 100 views and not many people have said anything yet!

 

[zzylstra]

I've blew up a 750 15 mins after I purchased it, that was 4 months ago and I'm still finding pieces of pistons everytime I ride. Blown up motors def set u way back financially, especially when it's more then a top end

 

[D-Roc]

I built a 10 minute motor once. It's an expensive learning curve that motor building thing....

 

[Roseand]

I built a 10 minute motor once. It's an expensive learning curve that motor building thing....

Wow that's rough..
I can't believe it though. After 18 years, do motors sometimes just go? I dunno exactly what happened. I will know more once I tear it completely apart. Those are just pics of me taking the head off on the lift. I had to see how bad it was.

I'm pissed and pretty sad at the same time. School started and I don't have money to rebuild it right now. So I'm done for the season..But I guess i ended the season with a bang!

 

[Half flip95]

I built a 10 minute motor once. It's an expensive learning curve that motor building thing....

I did one of those.

 

[Sparkplug]

I killed a stock 701 this year. The first day of a 5 day weekend at Santa Barbara. Luckily I brought a spare engine. It's gonna happen if you ride long and hard enough. I got plenty of hours from mine to be worth it.

Good luck on your new motor man.

 

[OCD Solutions]

The worst part of blowing an engine is the hit your confidence takes. I used to run some pretty fast rivers and rapids, (+40mph) when I thought my ski was bulletproof. Once I lost that first motor, I wouldn't touch the scary stuff and started riding very conservatively, and always close to the launch.

I had to ditch the Seadoo and start riding Yamaha standups before I got any sense of confidence back.

It could have just been that engines time but I would pay very close attention when you pull it down. That's a lot of years and hours on that engine so it's understandable if there's more than one issue with it. The good news is, there's not too many parts involved so a good rebuild should have you running again for just as long. I know you're on a budget but don't cut any corners putting it back together or it will just cost you more in the long run.

 

[Little Trumps Super Jet]

I feel you man, im in highschool and go through skis like underwear but I have a very good job and fix ups skis and bikes in my shop which is my other job. point is, I bought my full built sn for a good deal but still a lot of money, idling out of the long buoy zone, it seized fully, I hadn't even left the no wake zone!!!! lmao. then right after, being towed back, my exhaust, pump and trim bolts fell out! I was pissed and like he said, confidence shot. so I bought my girlfriend a built but reliable blaster for a smoking deal, waiting to build my motor. best thing if you want stock is buy an old 701 wave runner or b1, swamp in motor, then sell the rest to cover your motor.

 

[Roseand]

Yeah I'm in highschool too, senior year. Wish it was still summertime so I could at least work more than just weekends. Gotta save up a decent amount because I've still got some other stuff to spend money/pay off. Might have to not go so crazy on my winter build.. I wasn't planning on my engine blowing up..
I don't know how bad it is, I'm pretty sure my crank went too. The case was hot enough to burn you, maybe a crank bearing went and overheated my rear piston.
I want to rebuild it myself, it's a good learning experience and I've heard mixed things about sbt motors.

Sent from my XT907 using Tapatalk 4 Beta

 

[MADMAT]

Oh man!! Pro X pistons and SBT crank from jetmaniac IMO.....keep it cheap as you can! We still have season left!

 

[Roseand]

Yeah we'll see what I'm going to do. Still don't know the whole extent of the damage until I tear it apart.. I'll get more pictures up when I tear it apart.Not sure when because I've gotta tow it back and get it home so I can strip it down. I'm gonna examine and go through absolutely everything I can when I tear it apart to see what exactly happened, and to see if I could have even avoided it. I'm going to make sure this never happens again, or at least not for a long time..
It's so frustrating!!!

 

[Roseand]

I updated the first post with some new carnage!
Yeah my crank is toast for sure!! That's all the damage I've seen so far, I'll know more once I completely tear it down.
Here's some pics of the cylinders, they're not bad!

The Cylinder that the piston skirt broke in didn't even get damaged really.. I believe that's the middle picture

 

[imabadfish]

Wow man... The crank makes it so much worse sorry... If you were to go the route of attempting rebuilding this and using that cylinder you'd need a crank, head, pistons, gaskets, etc, and possibly a freash hone... you may end up spending more money than just replacing it. Personally I would sell that cylinder to some one looking to do a BB and use that money to buy another short block. good luck

 

[Roseand]

As long as the cases aren't too bad(there's some nicks and scoring inside of the cases that I can see, nothing crazy) I'm looking at 750$ more or less, including boring the cylinders over a little bit. Unless I go the SBT route, that's still around 650$.. but I dunno. Quite mixed feelings I've heard about SBT motors.. I hear they don't use many OEM parts in their rebuilds too. And I hear they aren't built for performance.
I'd like to rebuild it so I know it's all fresh, rather than buy a used motor. Who knows, a used motor could have a worn out crank and still have good compression. Heck, a motor could have good compression yet grenade the first time you use it. You never know with used stuff.. I need something reliable!!!
I'm going to be so extra cautious on this next motor...

 

[tor*p*do]

this is why when it isn't running right, stop running it immediately
your "wire" problem was probably a lean condition.
your "limp" was actually seizure
Strip the carb and check jet sizes
It probably wasn't re-jetted when they put on the pipe
and/or the internal fuel filter is clogged

 

[Roseand]

this is why when it isn't running right, stop running it immediately
your "wire" problem was probably a lean condition.
your "limp" was actually seizure
Strip the carb and check jet sizes
It probably wasn't re-jetted when they put on the pipe
and/or the internal fuel filter is clogged

Yeah that's what I'm starting to think happened the other day.
However, I am 100% sure that I was having spark plug wire issues before(well over a month ago). I had wires completely split and broke that I had to cut back, and after that it ran perfect. It's ran nearly flawlessly all season. I've put probably around 50 hours on it myself. Originally all it had was a b pipe. I added a 9/15 hooker, a scoop grate, and a CDI with rev limiter set to 7750 rpms.
The last time I road it before it blew up, it was running a little funky just like it does when the wires start to break, and sure enough when I pulled the plug boots off, the wires were broken again. So that's when I redid my plug wires and put new ones in, and the day it blew up that was the first time with the new plug wires..
So I had it out, started out running a little rough(just needed to warm up a little bit), then it cleared out and was running good for 15 minutes, just with a little bit of low end hesitation. I mean like barely noticable, just not that crisp snap. So I honestly didn't think anything of it, I thought maybe my terminals weren't getting that great of a connection. Honestly when it started to not run perfect, all I was thinking is that I might have messed up my coil when I installed the wires, and the connection was just getting worse. Because that's what it felt like to me!! I wasn't expecting it to blow up on me, I never would have guessed that's what was happening. I was in absolute shock when I looked down those plug holes and saw the metal..

Now someone brought this to my attention, and I'd like some insight on it as well.
Since I've got a 9/15 hooker prop, that's allowed my ski to rev up more.. And when I go on highspeed runs(which I don't do that often, and not for long periods of time), my engine has to rev more because of the pitch of the prop.
Basically, the person that mentioned this is against modding stock stuff, because the stock stuff has been built to spec, and isn't made to handle a different prop or pipe that revs higher. And the higher revving takes a tole on the motor. Just to let you guys know, this ski has had an OEM aluminum prop for 18 years until I changed it mid season to a 9/15 hooker. What do you think about this person's take on mods like a prop+pipe that raise the rpms? I'm curious to what you guys think.

I mean I try my best to let off the throttle when I'm in the air, but there's times where it sounds like I'm hitting the rev limiter for a split second, and I don't try to do it. My limiter has been set at 7750.

Thanks alot for the insight! I really appreciate it.

 

[JetManiac]

Of course, the pipe and your freestyle riding are harder on the motor than just putting around the lake with oem junk. However, you had an old motor with unknown history, unknown hours, and unknown carb jetting and tuning. It blew up.
You arent the first or the last, but you can tune a high performance, limited type of motor to last, but you are making always making tradeoffs for higher performance.

 

[Quinc]

Yeah that's what I'm starting to think happened the other day.
However, I am 100% sure that I was having spark plug wire issues before(well over a month ago). I had wires completely split and broke that I had to cut back, and after that it ran perfect. It's ran nearly flawlessly all season. I've put probably around 50 hours on it myself. Originally all it had was a b pipe. I added a 9/15 hooker, a scoop grate, and a CDI with rev limiter set to 7750 rpms.
The last time I road it before it blew up, it was running a little funky just like it does when the wires start to break, and sure enough when I pulled the plug boots off, the wires were broken again. So that's when I redid my plug wires and put new ones in, and the day it blew up that was the first time with the new plug wires..
So I had it out, started out running a little rough(just needed to warm up a little bit), then it cleared out and was running good for 15 minutes, just with a little bit of low end hesitation. I mean like barely noticable, just not that crisp snap. So I honestly didn't think anything of it, I thought maybe my terminals weren't getting that great of a connection. Honestly when it started to not run perfect, all I was thinking is that I might have messed up my coil when I installed the wires, and the connection was just getting worse. Because that's what it felt like to me!! I wasn't expecting it to blow up on me, I never would have guessed that's what was happening. I was in absolute shock when I looked down those plug holes and saw the metal..

Now someone brought this to my attention, and I'd like some insight on it as well.
Since I've got a 9/15 hooker prop, that's allowed my ski to rev up more.. And when I go on highspeed runs(which I don't do that often, and not for long periods of time), my engine has to rev more because of the pitch of the prop.
Basically, the person that mentioned this is against modding stock stuff, because the stock stuff has been built to spec, and isn't made to handle a different prop or pipe that revs higher. And the higher revving takes a tole on the motor. Just to let you guys know, this ski has had an OEM aluminum prop for 18 years until I changed it mid season to a 9/15 hooker. What do you think about this person's take on mods like a prop+pipe that raise the rpms? I'm curious to what you guys think.

I mean I try my best to let off the throttle when I'm in the air, but there's times where it sounds like I'm hitting the rev limiter for a split second, and I don't try to do it. My limiter has been set at 7750.

Thanks alot for the insight! I really appreciate it.

If that where the case than everyone heres ski would blow up. It sounds like you had an issue with your carb settings or your crank was going out already or maybe even both. Once you get put back together with decent parts you will most likely have another 20+ years of life on the engine.


Talk to Jetmaniac about a new crank and a new topend.
http://www.x-h2o.com/threads/106417...tyle-Ported-Top-End-Kit-650&highlight=porting