75hp Chrysler,Carbs too Rich-where to start?

[JDA45]

Cleaned carbs three times checked floats with guage.Set Idel mix screw by turning in to just bearly seated then out one and a quarter turns.What else can make it run to rich. White smoke and stronge gas smell that will burn your eyes and water in test tank has black oil in it.Set base timing to 10 BTDC Because it want start at 0 TDC. New gas full tank with 50 to 1 mix. New plugs #1 & #2 plugs come out black & oily. #3 comes out clean & shiny. Just bought boat and have no history to go by.<br />Please give suggestions on what to try. Thanks John allen

 

[Yepblaze]

Re: 75hp Chrysler,Carbs too Rich-where to start?

What else can you do? Perhaps buy a new computer controlled four stroke.<br /><br />No, but really what you describe might be considered normal.<br /><br />How's it run on the water"?<br /><br />A two stroke motor by it's basic design will emit a lot of unburnt fuel/oil mix. That will accumulate in the barrel or dribble from exhaust area when run on hose. Not at all uncommon.<br /><br />White smoke is steam or water vapor spray.<br /><br />Perhaps a decarb treatment, or new piston rings might improve combustion, but I believe what you see as problematic might be considered normal.

 

[turtle1173]

Re: 75hp Chrysler,Carbs too Rich-where to start?

JDA45,<br /><br /> Did you ever get your problem fixed??<br /><br /> If you have white smoke, I would get that problem fixed first. Chances are good that it is a blown head gasket and water is getting into that #3 cylinder. I had a similar problem on my 85HP.<br /><br /> Did you disassemble the carbs or just spray carb cleaner in them?<br /><br /> My manual states that you should start 1 turn out from barely seated. This would be a leaner mixture than you are running at 1 1/4 turns.<br /><br /> Yeah, don't worry about the oil in the test barrel.<br /><br />Shane

 

[speedwrench]

Re: 75hp Chrysler,Carbs too Rich-where to start?

First, get manual if don't have one.<br /><br />Need to find problem with #3 first. Can't adjust carbs if engine has other problems. Clean plug generally means water getting into cyl. Run compression.