1997 lawn Boy motor switch

[tjd]

I have a 19 gold series that I am trying to swap out the engine with another. The current engine has a plastic carburetor and a primer bulb, the new engine I located has a walbro carburetor with a manual choke. Everything was going great on the change until I noticed the difference in how the throttle cable hooks up. The old carburetor will fit on the new engine, but I noticed their is a port (circuit) between the carburetor and intake that the old engine and carburetor do not have. Any help is appreciated to help me finish this job

 

[tjd]

I am a new member and noticed in a previous thread this is the same tiny hole between the carburetor flange and intake. The new motor has it and the old one does not. Wondering if the engine will run right if I take the old carburetor and bolt it to the new engine? The model number of the mower is a 10401 and I am trying to restore this mower