Sometimes acts like doesnt want to cut off , Possible not running blower enough?

[volleybiggs]

Sometimes my 1996 mercuiser 6cy acts like it doesnt want to cut off. When I turn it off it runs rough a few seconds and then cuts off. It does not happen all the time. But when it does it takes several times of cranking to start. Is it because I dont run the blower often enough? I thought the problem of it not starting is from vapor lock. Any thoughts?
Thanks!

 

[Utahboatnut]

Re: Sometimes acts like doesnt want to cut off , Possible not running blower enough?

Be careful with this condition, as it is possible to have the engine run in reverse while it is dieseling thus sucking water back IN. It may have happened already and caused a hard start condition. There have been a number of service bullitens regarding engine run on and your engine is one that falls into the bulliten. A couple things to try, after running hard for any distance after bringing it down to idle let it idle for a few minutes before shutting it down. Use a higher octane gas, get the timing checked, I would lean toward the timing. but try some of the other suggestions and see if it improves. If it does run on hit the key to start it again and let it idle some more.

 

[HT32BSX115]

Re: Sometimes acts like doesnt want to cut off , Possible not running blower enough?

Sometimes my 1996 mercuiser 6cy acts like it doesnt want to cut off. When I turn it off it runs rough a few seconds and then cuts off. It does not happen all the time. But when it does it takes several times of cranking to start. Is it because I dont run the blower often enough? I thought the problem of it not starting is from vapor lock. Any thoughts?
Thanks!

Howdy,


Yeah. vapor lock is a possibility. Don't let it run-on ("diesel") for long though....... if it does it every time you shut down you run the risk of it turning the wrong way and sucking water into the exhaust, causing a hydrolock.

Have a look at the following links (PDFs) Merc SB 97-17 ("Running-On") and 99-7 ("Vapor-Lock")

http://forums.iboats.com/attachment.php?attachmentid=98326&d=1308146456

http://forums.iboats.com/attachment.php?attachmentid=97740&d=1307888847

There's some step you can take that should help!


Regards,


Rick