Should an engine Diesel when the kill switch is activated while boat is moving

[Robertpel9]

Yesterday when i came off plane i am not sure what happened (maybe i hit it) but my kill switch (Dead man - whatever you want to call it) lanyard came off while the throttle was still 20% forward. The engine dieseled for about 10 seconds while i frantically tried to put the switch back on. when i did that the engine smoothed out and i drove it around the restof the day just fine

Last year with my old Boat i made the mistake of turning the engine off while still moving and my engine dieseled and hydrolocked - Visions of that were going thru my head while i frantically reattached the switch while this engine was dieseling

When that kill switch is activated shouldnt the engine just stop and not diesel at all. Somehow i got lucky and everything is fine with my boat but i dont want to go thru this again as the hydrolock with my old boat was a nightmare

Boat runs perfect - is something wrong here??

 

[mkast]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

Boat runs perfect - is something wrong here??

If the engine runs perfect, I'd be worried.

 

[Robertpel9]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

My worry is from the fact that it may run perfectly fine but why did it not just shut down when the kill switch lanyard was pulled off?? Dieseling can cause a bad hydrolock and thrash an engine (Went thru a hydrolock with my last boat)

Why did it do this??

 

[diehard]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

your kill switch shuts down the ignition it is not an engine break so the moter continues to spin for a few seconds and when it diesel the moter can spin backwards and suck water threw exhaust ..

 

[Robertpel9]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

Have not done any electrical work and all the electronics seem to work fine and are stock from when new- that is odd. I wonder why it did not hydrolock up considering it dieseled for a good 10-15 seconds????

 

[gadget73]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

If the throttle is open, it can diesel for a bit if the ignition is cut off. It means the plugs are hot enough to ignite the fuel/air mix. If the plugs are old, buildup on the electrodes will heavily contribute to this. If the plugs are recent, it might just be a symptom of cutting the ignition off suddenly above idle speed. A lot of carb'd car engines will do that if the idle is too high.

 

[Robertpel9]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

I googles this and saw other people have the same problem and end up with water in cylinders, hydrolocks, etc

I wish to be honest i could just bypass the kill switch but i am sure if God forbid something bad happened there would be liability issues, etc.

I do not believe the plugs have ever been changed, i will go ahead and do that this week. Considering my oil is clean as a whistle and the engine is running just fine is it safe to assume i dodged a bullet here and did not cause any damage?

 

[bigskiohio]

Re: Should an engine Diesel when the kill switch is activated while boat is moving

i dont think there is anthing you can do about it. just one of those gambles in boating. mine does it if i dont let it idle down bfore is hut it off. i need to adjust my throttle cable, i think. but under power that might hurt.