4.3L Merc io backfire problem

[Tmitchel_5188]

I have a 1992 merc io 4.3L v6. I get some back fire. This happens when I'm trolling in rough water (1-3' waves). I have replaced both exhaust flapper valves, but I still get the back fire. The only way I can get rid of it is to take it easy when I take off. I think that I'm getting a little water up in the exhaust with the wave actions.<br /><br />Any ideas???

 

[Bondo]

Re: 4.3L Merc io backfire problem

Backfires are Usually caused by a Lean condition....<br />Check out your Carb... Low float levels Could cause this in rough water...

 

[Tmitchel_5188]

Re: 4.3L Merc io backfire problem

How do I adjust the carb and make it a little richer????<br /><br />Thanks

 

[Bondo]

Re: 4.3L Merc io backfire problem

Depends on Which Carb you have......<br />Buy a Manual....

 

[Tmitchel_5188]

Re: 4.3L Merc io backfire problem

I took it out today for the 1st time this year. It ran ok, but I noticed a little spark knock. Related to a lean condition????

 

[wheels4]

Re: 4.3L Merc io backfire problem

Yes you are lean.Lean condition will cause detonation.

 

[Bondo]

Re: 4.3L Merc io backfire problem

A Lean condition, or advanced Timing will cause Spark-Knock....<br />Detonation will reduce an engine to Junk in Minutes....