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1978 Mercury 200 20HP 2 stroke outboard

T

TJ Throne

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I am working on a Tillotson BA2C carburetor for a 1978 mercury 20hp. The main fuel jet is missing, it wasn't in the carburetor. No wonder it didn't run properly. The carb requires a 0.057 main jet and all I can find is a 0.056 jet. I know that is only one thousandth difference, but I am concerned about running at full throttle. Will that 0.056 jet be too lean.
 
From what I was able to find across multiple years and carb designs, .056 was the leanest offered, the standard jet was .057, your serial number is greater the 470 XXXXX? Correct?
 
yes 4957481. I purchased the 0.057 but have the 0.056 installed in carb. The carb is not on motor yet so I don't need to deal with taking it back off. Might as well use the right part. Thanks again
 
Then the .056' would be the preferred orifice... I'm 36ft above sea level here in Florida. No need to re-jet for me! But a good observation, I actually thought about the .056" application but TJ said it didn't have a jet in it so I went to sea level as my base.. TJ, where are you?
 
I think the 0.057 should work. I am in southern Illinois and the places that I fish vary from 300ft ASL to less than 1000ft ASL in northern IL. Thanks for looking out for me Droid. Much appreciated.
 
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