2006 3.0 Mercruiser slow shut off

[Tommyd13]

When shutting off engine after a while the engine will not die completely. Its as if the fuel pump is still pumping fuel to keep the engine running. The symptoms sounds like the engine is starving for fuel to keep running. I tried pulling out of gear and leaving the boat idle for a while to burn off excess fuel but it still does it. Any thoughts on what could cause this or what the fix could be. Thanks.

 

[89sandman]

Sounds like dieseling due to a poor carb. Shutting it off while still in gear my help some.

 

[Tommyd13]

Can you clean the carb to prevent or do you have to replace\rebuild carb to fix?

 

[Bt Doctur]

high engine temperature
improper timing
poor fuel quality
excessive engine carbon
for starters , doubtful its a carb issue

 

[guitarsnlikker]

my 2010 3.0 TKS did that too. Turned out that it was all a timing issue. Check your timing first I would suggest. Base timing instructions are posted here and in service manuals. You will need a jumper wire with bullet ends (Quicksilver 91-818812A1).