FX-1 Waterbox Carnage...Why?

[aj91799]

Just got my ski out to do check ups before I ride it this week. Put gas in the tank and a little in the carb to prime it...started and ran for 10 seconds, put the hood on (in the sun) and wiped the whole ski down, then went to start it again to check for exhaust leaks and...BOOOM... now I have a 6 part waterbox. I have an extra but what should I do to prevent this from happening again?

 

[newbee]

I would say it's was gas fuels. Maybe the carb leaking some. Then a good backfire

 

[SXIPro]

I blew up my waterbox in my square when the cdi crapped out.

 

[E350]

Interesting post. Yesterday we took out the SN SJ and the FX1. The FX1 would start and then die and then not start. I popped the hood and my wife said "look it's smoking." And sure enough the "radiator"-type hose that goes from the metal muffler to the waterbox had popped off the muffler. I put it back on and the ski did the same thing. It started then died.

The reason it was dying IMO was that the carburetor couldn't get air, it was getting exhaust which was depleted of oxygen.

So, I beached the ski. Left the hood off, and gently ran the engine until all the water which apparently had collected in the waterbox was pushed out the exhaust.

Something had to give. The waterbox was full of water and the exhaust couldn't get out.

No doubt if I had punched it with the hood off, or if the "radiator"-type hose hadn't popped off the muffler, my waterbox would have exploded like yours...

We skied again today, with no issues.

But I am going out right now to loosen the hose clamp which holds the "radiator"-type hose on the muffler.

 

[aj91799]

May have found my problem. Looks like I’m going to do a leak down test after I saw this. Could a leaky seal cause backfire?

 

[orangefinger]

residue and probably gas left over in water box , u might not be burning everything at time of ignition, or backfire , I had one blow in my blaster once that popped the hood up when it blew....

 

[Quinc]

residue and probably gas left over in water box , u might not be burning everything at time of ignition, or backfire , I had one blow in my blaster once that popped the hood up when it blew....

Blaster waterboxes blowing are the best! And by best I mean the loudest.

 

[E350]

Hmmm. Did you do a compression test prior to firing it up?

The reason I ask is because I have been known to not disconnect the fuel hose to the carburetor when compression testing which would introduce unburnt raw fuel into the crankcase and then exhaust system.

 

[SXIPro]

Blaster waterboxes blowing are the best! And by best I mean the loudest.

They definitely "go to 11".

 

[Boz Mon]

I’ve heard of this happening to stock boxes on fx1’s. Mine was leaking but it never blew up. I picked up an aluminum aftermarket sn box now.


Sent from my iPhone using Tapatalk

 

[bored&stroked]

I blew up my waterbox in my square when the cdi crapped out.

Me too. Cranked it two seconds then backfire and bye bye waterbox.

 

[Myself]

It can literally happen just from a spark plug going bad. One quits sparking and the fuel in that cylinder doesn't ignite so it gets pushed into the exhaust. A few revolutions later it has built up and finally it's rich enough the pulse wave from the other cylinder ignites it........kaboom!