merc 500 carb question

[dtruck]

I have a 1975 merc 500. The numbers on the carbs are ka27at506.On top of the bowl cover there is a jet and a barbed fitting.A small fuel line runs from the fitting to another fitting on top of the carb body.The rebuild kit does not show these on the bowl cover nor does the manual.I am simply ignorant as to what function they serve as I cannot find any info anywhere.My uneducated guess would be someone has changed the carbs from original.
Any Knowledge or advice at all would be greatly appreciated.

Dave

 

[crem1]

Re: merc 500 carb question

There is a throttle linkage and the kits you get are for each carb unit, they are independent.
Are the bowls round as in the picture?

 

[dtruck]

Re: merc 500 carb question

that is the same bowl yes

 

[crem1]

Re: merc 500 carb question

The throtle linkage and the gas supply line are the only common threads between the two carburators