What is primer bulb and return fitting? For plane?
 

Hi all

As I need to source for a Walbro carb replacement, I see some have bulb primer and return fitting? What this for? and how this impact Rc plane engine?

Say if you have use the standard Walbro with no primer bulb and return fitting, what will happen when you replace the carb with one? My reason for asking because I want to get the correct replacement carb for my Zen G20.

RE: What is primer bulb and return fitting? For plane?
 

The primer bulb is there to fill the carb from the tank...It has no other function...the return fitting was connected to the tank so that fuel was returned to the tank and not pumped out on the ground....there is a one way valve in the system that keeps air from getting into the carb if the fitting is left open...A standard flat carb top can be used if the extra passage is blocked..I have used a 2-56 screw to block the hole, ground flush on the inside of the cavity under the diaphragm...

RE: What is primer bulb and return fitting? For plane?
 

So I can used them with my G20(the one from you) with no issue? You got a standard Walbro to sell ie without primer/bulb type? Its such a pain to get them over here....

RE: What is primer bulb and return fitting? For plane?
 

You can have the one I took off the engine before it was sent to you..I can run it on mine to make sure it works...Will send it today,

RE: What is primer bulb and return fitting? For plane?
 

Ralph,

Thanks! I will PM you with a tad more question. Thanks again!