Oh dang, what just happened

[SXIPro]

Here is a decent explanation of a leak down/air leak test:

http://www.jetskimechanic.com/home/e107_plugins/content/content.php?content.22

When I did mine, I pulled my carbs and my head pipe. Then I bought 2, 1.5" expandable plugs and 1, 2" expandable plugs from Lowes in the plumbing section. I used those to close off my intake and exhaust manifolds. I bought a cheap pressure gauge some fittings, and used those with a bike pump to pressure test my engine.

Do some searching on here too.

 

[Big Kahuna]

ummmmmmmmmm, before you rip apart your motor, remove the flame arrestors and make sure your carb butterflies are sync'd. Had a case on a buddies ski where it was running away, one carb was out of sync and it wold start free reving, the motor was getting air/fuel, it wanted more.

Sometimes it is something so simple that we all over look it.

 

[SXIPro]

ummmmmmmmmm, before you rip apart your motor, remove the flame arrestors and make sure your carb butterflies are sync'd. Had a case on a buddies ski where it was running away, one carb was out of sync and it wold start free reving, the motor was getting air/fuel, it wanted more.

Sometimes it is something so simple that we all over look it.

Very true. Mine ended up being a leaky primer. Primer fittings were below the throttle body instead of up top where the choke plate shaft was....ouchie

 

[Mark44]

Blocking the exhaust with your shoe or towel will stop the run away fast.

Mark44

 

[Matt_E]

Throw a shoe at it! :lmao:

GeeDub approved.

 

[7ford7]

I did throw a shoe at it, that did not work.

 

[ger87410]

I bet it wasn't a Nike.

 

[Techzan]

My '06 superjet started doing the same thing last year and has done it probably 5 times since. It's scary as hell when it happens. I've been told the best way to kill the engine is the pinch the fuel line. I tried everything from pressing the stop button over and over, to yanking the spark plug wires, to holding my palm up against the flame arrestors. So obviously I don't know exactly what I'm talking about but I now believe it's my butteflies in the carb's. So next time this happens, which is only when it's out of water, I'm going to immediately try to turn the wheel that the throttle cable winds around next to the carbs. I have a hunch that will fix the immediate problem. I've been told by a jet ski mechanic not to worry about this happening in the water. Hopefully he's right.