4.3L Mercurser Diesels Backfires on shutdown

[GAV10]

Just bought a used 19 ft Stingray with a 4.3L V-6 Mercruser, 97 hours on it. The engine runs very well except it diesels and backfires for 10 to 20 seconds after shut down. This is a carb. model, not EFI. Any suggestions on what would cause this.<br /><br />My first post.<br /><br />Thanks...<br /><br />Mark

 

[Bear]

Re: 4.3L Mercurser Diesels Backfires on shutdown

First post? <br />Try here:<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=forum&f=24&submit=Go <br /><br />Good luck!<br />

 

[dmorley]

Re: 4.3L Mercurser Diesels Backfires on shutdown

I've got the exact same problem. At first my spark arrestor was pretty plugged up and the problem when away after I cleaned it. Problem came back a few days later and a boat mechanic, who was too booked to work on it, told me I would need an entire carborator rebuild. Unless somebody indicates otherwise that is what I'll have done.

 

[akita]

Re: 4.3L Mercurser Diesels Backfires on shutdown

COULD BE CARB IF IT IS LEAKING SOME GAS INTO THE INTAKE. BUT IF IT ISNT THE IDLE MAY BE SET TO HIGH. BOTH OF THESE WILL CAUSE THIS.

 

[roscoe]

Re: 4.3L Mercurser Diesels Backfires on shutdown

A lean running engine will do this. Carb adjustment or cleaning may fix.

 

[moderator1]

Re: 4.3L Mercurser Diesels Backfires on shutdown

Moving to I/O questions.