Trying to fix a 2 cycle grass trimmer/edger. Don't know much about small engines. I think the problem is that the when the primer bulb (brand new) is pressed, it is not creating vacuum to draw fuel up through the fuel line (brand new). Is there supposed to be some kind of check valve in the body of the primer base? Searching on how these are supposed to work, the best article I saw was talking about a walbro carb (mine is an old Zama C1U-W7C) :
"It pumps fuel sitting in the top cover back into the fuel reservoir. This creates a vacuum. Fuel is pulled from the fuel reservoir, into the upper fuel chamber, through the fuel filter, down into the lower fuel chamber, and up through the low speed fuel mixture lines."
-How Does the Primer Bulb on a Walbro Carburetor Work? | eHow.com http://www.ehow.com/how-does_5598444_primer-bulb-walbro-carburetor-work_.html
If I tip the gas tank so the fuel return line (brand new) is submerged in fuel and press and release the bulb, fuel is drawn up the return line to fill the bulb. My feeling is that that shouldn't happen but, again, I don't know much about 2 cycle engines. In my mind what should happen is 1. bulb is pressed forcing air down return line into gas tank 2. bulb is released creating vacuum, check valve on fuel return line closes stopping flow back up return line and vacuum is filled by fuel being drawn through the fuel filter and up the other fuel line. Is that how it works in a perfect world?
If so that means that A) I buy a new primer base assembly for $16+shipping B) Try to find some kind of check valve to put in line between primer bulb and gas tank on fuel return line C) Throw the stupid thing in the trash and get a different weed whacker. I'm only like $20 of parts into this free trimmer a friend gave me. I really don't want to nickel and dime myself to death and end up spending what it would cost to get a new trimmer on repairing one that is already 10+ years old.
Any help would be much appreciated.
"It pumps fuel sitting in the top cover back into the fuel reservoir. This creates a vacuum. Fuel is pulled from the fuel reservoir, into the upper fuel chamber, through the fuel filter, down into the lower fuel chamber, and up through the low speed fuel mixture lines."
-How Does the Primer Bulb on a Walbro Carburetor Work? | eHow.com http://www.ehow.com/how-does_5598444_primer-bulb-walbro-carburetor-work_.html
If I tip the gas tank so the fuel return line (brand new) is submerged in fuel and press and release the bulb, fuel is drawn up the return line to fill the bulb. My feeling is that that shouldn't happen but, again, I don't know much about 2 cycle engines. In my mind what should happen is 1. bulb is pressed forcing air down return line into gas tank 2. bulb is released creating vacuum, check valve on fuel return line closes stopping flow back up return line and vacuum is filled by fuel being drawn through the fuel filter and up the other fuel line. Is that how it works in a perfect world?
If so that means that A) I buy a new primer base assembly for $16+shipping B) Try to find some kind of check valve to put in line between primer bulb and gas tank on fuel return line C) Throw the stupid thing in the trash and get a different weed whacker. I'm only like $20 of parts into this free trimmer a friend gave me. I really don't want to nickel and dime myself to death and end up spending what it would cost to get a new trimmer on repairing one that is already 10+ years old.
Any help would be much appreciated.