Primer port

 It would help if we knew what engine you have. But...

Assuming it is one of the variations of the 912 engines, The Carbs have a cable controlled Enricher (Choke) and do not have, or need, a primer port.

<p>It’s a 912 uls. I bought it used and it comes with the electric primer.

Like Bill says,

a primer is not necessary, just use the choke, which is cable controlled (pull cable). If your engine has an electric actuator on the choke, I suspect that has been added and is probably a solenoid ? perhaps you could post a photo and a serial number of your engine.

 Manual primer pumps were used on the older 2-Stroke engines.

I am not aware of any electric Primer pump options for the 4-stroke 912 series.

Are you sure you are not looking at an Auxillary Electric Fuel Pump?

The AUX pump would go in the Fuel line in Series with the Engine Mounted Mechanical Fuel Pump. 

You might want to pick the brain of the person who sold you the engine. 

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A full set of Manuals for that engine, including installation instructions, is available Here.

It's not an auxiliary pump, ut's a solenoid. He canceled the choke and used this solenoid as primer. Pics include.