runaway idle

[roger cockroft]

hi I have a 1993 spx . just rebuilt carb with mikuni kit . it started and ran fine for a 1/2 hur , now it has a runaway idle. pop off is at 26 psi . does anybody got a clue ???

 

[hotrodssnova]

If it is a runaway (uncontrollable rpm with the dess pulled off) is usually from an idle setting that is set too high.
I am assuming you had this on a trailer and the engine revved up without you doing anything?
For the record, when this happens, hold the throttle wide open. This will shut it down.

 

[roger cockroft]

Thanks for the responds , It does it on and off water . If I pull the dess it die . If i hit choke it some times goes to normal idle ???

 

[TwoSmoker]

If you hit the choke and it goes back to normal you may have a lean condition which can lead to an increasing idle speed. What do the plugs look like after this happens? Did you set the idle speed with the low speed screws?

 

[Lothsahn]

If it is a runaway (uncontrollable rpm with the dess pulled off) is usually from an idle setting that is set too high.
I am assuming you had this on a trailer and the engine revved up without you doing anything?
For the record, when this happens, hold the throttle wide open. This will shut it down.

Why would opening the throttle shut down the seadoo? Wouldn't that just make it rev to the limiter and possibly damage parts (carbon ring) if it was out of the water?

 

[jhjesse]

Why would opening the throttle shut down the seadoo? Wouldn't that just make it rev to the limiter and possibly damage parts (carbon ring) if it was out of the water?

Just pull the choke.

 

[jhjesse]

You have an air leak most probably around the carb base gasket since you just had them off.
I would go back and make sure the carbs, intake etc are seated properly and all bolts tight.

 

[mikidymac]

Are you sure your throttle is closing all the way? It sounds like you might have gotten the throttle cable installed wrong when you did the carbs.
A lean runaway will not happen in the water.