Okay her is the Question: My friend and I had a disagreement about this: If a boat diesiels (runs after you shut the ignition off) does the engine run backwards and if so if you put the boat in reverse would it go forward.. Now I know what your thinking is these 2 guys have to much time on there hands!. So whats the deal?
Nope...unless you REALLY focked something upJ/K
In my experience, it's just the motor continuing to run(sort of) without a spark using the diesel principle (ie. compressing fuel and air in an already hot combustion chamber and allowing it to ignite)
Always cool when you pull into the hangout spot and go to shut her down....pop, POP, hiss, BOOF <------internet sound effects
The beginning stages of dieseling is the motor spinning in its designed direction. However, in alot of major cases that last little smooth spin up is the motor running backwards. So if you have your boat in reverse at that time (with a prop drive) yes it will go forward. If you have a jet and have it in reverse, it won't go anywhere. The reverse bucket down, it would draw water from that and try to shove it back through the intake probaby not making the boat go anywhere other than try to lift the transom upwards.
Running backwards doesn't make sense. :idea:
I'm no expert, but when my engine diesels, I turn the ignition back on and it fires right up. I may do this several times during long dieseling episodes.
If it were running backwards I don't think it would refire in the right direction that smoothly.
Just my .02
J
Oh, and I found this old thread because I have a question on this topic.
Does advancing or retarding timing affect dieseling?
Everything runs great, but sometimes when I shut down, it diesels. Sometimes up to 15 seconds or so. That seems like forever when it is happening.
Also, does dieseling itself cause damage?
J
Oh, and I found this old thread because I have a question on this topic.
Does advancing or retarding timing affect dieseling?
Everything runs great, but sometimes when I shut down, it diesels. Sometimes up to 15 seconds or so. That seems like forever when it is happening.
Also, does dieseling itself cause damage?
J
Yes, timing issues can cause dieseling, too retarded will cause exhaust valves to glow and ignite the fuel.
I have heard people say " you need to back off on the timing", I can't see how that would help, since the ignition is off and the plugs aren't firing. What jmherbert said about the timing being too far retarded, makes sense though.
Yes, timing issues can cause dieseling, too retarded will cause exhaust valves to glow and ignite the fuel.
^^^^That and too high an idle speed, combine to cause run-on.
(to first question)
I don't think an engine could take being blasted to reverse rotation, the timing chain would probably be the first thing to break.
I had a single cylinder 2 stroke that I could get to run backwards. It was on a 1983 Honda Odyssey 4 wheeler. All I had to do is shut it off, and when it almost stopped running, turn it back on and sometimes it would run backwards.
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