engine running out of control

[rusty nail]

at the end of the season i had the seadoo out for quite a long time pulling the kids at about 3/4 throttle on the tube and knee board. We were actually almost done for the year and the seadoo throttled up out of control so i pulled the lanyard and it stopped right away. I hit the throttle without running the machine to see if the cable felt like it was stuck and it felt fine. However that does not mean it was not stuck open in the carb. I fired up the machine again and immediately the seadoo throttled out of control again. I again immediately pulled the lanyard.

Before i dig deep into the seadoo and see if the cable is stuck somewhere can someone give me advice on some other possible problems with these symptoms?

This is a 2000 951 carburated gtx.

Thanks.

 

[mikidymac]

Did this happen in the water or out?

 

[rusty nail]

in the water.

 

[mikidymac]

If it is happening in the water then it is most likely the throttle sticking. Probably a cable issue.

 

[rusty nail]

That is what i was thinking, but i did not know if stoke engine could "diesel". I will look at the throttle cable through the winter. It will be a project.

 

[mikidymac]

A two stroke can runaway from an air leak but this will happen out of the water not in the water with a load on it.

 

[rusty nail]

This is good to know. Thanks.

 

[rusty nail]

so i pulled off the carb and the throttle cable was off the mount. put it all back together and started it up and it is still racing.. The seadoo is in my garage out of the water. Any thoughts?

 

[mikidymac]

Are you sure the cable is adjusted correctly so that there is slack in it at idle?

The oil cable could also be holding it open or the idle screw adjusted in too far.

 

[rusty nail]

I will look at those Wednesday . I thought I made sure there is slack in the cable. For arguments sake, if the cable is tight should the engine not just run a little faster and not race out of control? I will also check the carb gasket .

 

[mikidymac]

If it revs out of control to maximum rpm then it’s probably an air leak but typically the kill switch won’t stop it because it’s using the lean burn heat to ignite instead of the spark like a diesel.

 

[rusty nail]

When i did the run test i did not have the air silencer or the exhaust LH resonator installed. Could this be the reason why the engine wanted to run lean and race? I figured this would not make a difference with the air/fuel mixture and cause it to run differently.

 

[rusty nail]

ok. so i looked again where the idle screw is located and there was a little space between the screw and the throttle assembly. I backed off the tension on the throttle cable so it touched the idle screw and left a little more slack, put everything back together including the air box assembly and exhaust reasonator, and it runs and idles beauty. Now i need a water test. Cannot wait till next summmer. Thanks for your patience and help MikidyMac.

 

[rusty nail]

For the future. Do you have an idea on how to take the exhaust gas outside when working in a garage? Can i simply hook up a pipe to the exhaust outlet or will that affect the idle because it will be a little more restrictive?

 

[mikidymac]

It will not change the idle. The best way to set the idle is with the ski in the water.

Once the idle is correct be sure to double check the oil pump setting as this will change with idle adjustments.