1988 300 da raw gas fro exhaust smell

[oilmatt]

I have a 1988 Sea Ray 300 with twin MerCruiser 350Z. They have Quadrajet Rochester carburetors. I had the carburetor rebuilt and the engine tuned. I have a raw gas smell coming from the exhaust also a bit of Grey smoke. Can anyone tell me what else to look for?

 

[Quint4]

Possibly a spark plug not firing? .......all spark plugs boots on good and tight?

 

[oilmatt]

Checked all boots. Had mechanic check plugs (he tuned it up). Engine not running rough except on start

 

[JVM225]

Is the choke working properly?