Super Jet Blew my hood off. Almost blew my head off. Stripped every head bolt.

[zyxwvu44]

Already did, thanks!
Jesus! There were that many fumes? I would have never thought engine bay explosions on these things were a "thing". The sound it made was awful. Like PFOOOMP! would be a good descriptive word. I'm kinda glad the hood flew off, who knows what else could have happened if the strap held.

I've seen it happen on a stock rn. Gas had been sittin in the hull for a while, the guy turned on the bilge before riding. BOOM. The hood blew off and put several large cracks straight through the middle of the fiberglass of the hood. He ended up using about 50 zipties to hold it together so he could ride for the weekend!

 

[tor*p*do]

and that is why Kawi put a blast relief port on the 750sx hull

 

[kraqus]

Another reason to wear a Helmet.




Benny

 

[TheBuzzard]

and that is why Kawi put a blast relief port on the 750sx hull

its called the explosion cap and its on all 300sx 650sx 750sx sxi & pro sxr800.

 

[waxhead]

So was it the head hitting the hood that took the hood off or was it a combustion inside the hull

 

[Scraggly]

Already did, thanks!
Jesus! There were that many fumes? I would have never thought engine bay explosions on these things were a "thing". The sound it made was awful. Like PFOOOMP! would be a good descriptive word. I'm kinda glad the hood flew off, who knows what else could have happened if the strap held.

A friend had a wammer hull busted up pretty good because of fumes and a bilge wire shorted out. Hood was ok and the hull sides to the beating if I remember correctly.

 

[sharkcus]

So was it the head hitting the hood that took the hood off or was it a combustion inside the hull

It was the combustion (fireball). I don't think the head physically left the motor, just lifted up lots.


What it looked like right after the lake



Obviously, the stator side cyl had the problem


Head. The clean one is the stator cyl. The head is still in good shape.


Good (rear) plug


Stator side plug (that lifted)


Cyl looks to have survived intact.

 

[Dutchie]

Told you it was a gas cloud

Ar your spark plugs the correct ones for this head / engine ? the look like short plugs

Gr,

 

[jdmforlife]

X2 on the plugs looks like hs plugs you should be running Es plugs

Told you it was a gas cloud

Ar your spark plugs the correct ones for this head / engine ? the look like short plugs

Gr,

 

[Yami-Rider]

X2 on the plugs looks like hs plugs you should be running Es plugs

X3

looks like he's running stock style br8hs plugs, but needs to be running br8es.

 

[tor*p*do]

X3

looks like he's running stock style br8hs plugs, but needs to be running br8es.

agreed. but that would not make it blow up

 

[Wipeout]

X3

looks like he's running stock style br8hs plugs, but needs to be running br8es.

Why? And when does it make since to switch?

 

[XJCrawler]

Aftermarket heads require the longer ES plug and stock heads use the HS plug

 

[sharkcus]

Hmmmm. Swapped plugs with another ski awhile back, didn't even dawn on me they might not be the ES. Ooops. But as mentioned, that wouldn't have caused this. They have been in there for at least 2 prior rides. What I did notice is that my head bolts didn't go that far into the holes. Only about half way. These were stock head bolts from a 650. I wonder if this head is thicker than stock.

Edit: Just thought of something. Having the non ES plug would lower your compression a bit, wouldn't it? I wonder if it would be noticeable.

 

[MADMAT]

Yes a AM head is thicker than a stocker and would require longer bolts ( I think, right????). I think you just solved your problem! It has to be that!

I have heard of people running shorter pulgs with no issue and no noticable performance loss..

 

[Balduccimoto]

Wow you definately ignited fumes in the hull. Kawis have a cap on top that is press fitted in, instead of blowing up the hood it will blow the cap. If I had to speculate, i'd say the head was loose when you were riding and unburnt fuel was leaking into your bilge. You may not have noticed; I've seen engines run flawlessly with serious issues happening. I would take a good look to make sure battery/starter/bilge or any electrical connections are tight and clean to be on the safe side.

 

[txsuperjetfreak96]

Did u have the head torqued properly, should b rechecked after every couple of rides


Jeremy

 

[Proformance1]

You should always check every part you change, for installed length. Plugs, bolts, etc and should use loctite or similar for head bolts. Think about short bolts and a short spark plug. Add in some detonation and the bolts back right out.

 

[sharkcus]

Yes a AM head is thicker than a stocker and would require longer bolts ( I think, right????). I think you just solved your problem! It has to be that!

I have heard of people running shorter pulgs with no issue and no noticable performance loss..

I didn't have a chance to measure the thickness, but that **HAS** to be the problem. The more I looked at these bolts...they could have gone a LOT lower into the head.

 

[Dutchie]

Now i know what the cap is on my x2.. it's a explosion cap