2003 rinker won't shut off

eric25

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Jun 16, 2011
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i have a 2003 4.3 mercruiser thunder bolt, after running for a while when i turn the ignition off the engine still tries to run any suggestions on fixing this problem
 

dubs283

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Jul 27, 2005
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Re: 2003 rinker won't shut off

tries to run??

as in dieseling??

also know as "run on"??
 

eric25

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Jun 16, 2011
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Re: 2003 rinker won't shut off

what causes it to diesel is it the timing?
 

CobiaXL

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Mar 8, 2010
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Re: 2003 rinker won't shut off

i have a 2003 4.3 mercruiser thunder bolt, after running for a while when i turn the ignition off the engine still tries to run any suggestions on fixing this problem

Check timing.
 

mpdive

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Apr 23, 2011
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Re: 2003 rinker won't shut off

i have a 2003 4.3 mercruiser thunder bolt, after running for a while when i turn the ignition off the engine still tries to run any suggestions on fixing this problem

Two most common causes are Idle speed is set a bit high or carbon deposits on the top of pistons. Very common condition and usually solved with idle speed adjustment. If it still persists, try a top end cleaner designed specifically to remove the carbon deposits. The condition is called "dieseling" and is caused by the carbon deposits glowing red hot. When the engine is shut off, the hot spots are hot enough to continue detonating fuel. Hence the name dieseling since that is the way a diesel engine works via glow plugs. Try the idle speed first and then the deposits second. If it were my boat, I would mist water with a spray bottle down the carb while running the engine at 1000 rpms. Done slowly it is very effective at removing carbon via steam, and we did it at the dealership all the time. Again, just what I would do
 

Don S

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Aug 31, 2004
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Re: 2003 rinker won't shut off

Mercruiser even put out a service bulletin on the problem, and the cures.
 

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