rcgood

Why would gas not make it's way up to the carb on this motor? I have a Walbro carb on it (and it's actually the older zdz-80) but when I flip gas doesn't come up to the carb in any choke/throttle position. I checked all the tubing and tank and they're all OK.

mrbigg

My Feedback: (21)

pump is shot. I have a 160 doing the same thing. I was told to throw a rebuild kit in it.

FalconWings10

My Feedback: (4)

Could be a weak or faulty diaphram. Keep priming until you can get it to start, look for bubbles in the fuel line. Do you have your vent line setup?

rcgood

I forgot to mention that I did put a new repair kit in the carb. Gaskets, diaphram, needle valve, etc...I was thinking that maybe I put something in the wrong way but I did double check everything and put them in there exactly how the previous ones were.

The problem is that I can't even prime it. The fuel never makes it to the carb no matter what I do. The vent line is setup and works.

Tony Hallo

Try pushing the metering diaphram down to vent the pump, once the metering cavity is full of fluid, the diaphram can do it's job. Just experienced the same problem on a recently rebuild carb. I used a small allen wrench to push the diaphragm, your pop-off pressure is higher than the pump pressure. Search for the Walbro service manual online, it might help you understand the problem. I have the manual saved and it's too big to upload. You have fuel right up to the regulating valve, the pump just can't get it opened.

FalconWings10

My Feedback: (4)

Great input Tony. I was having the same issue.

rcgood

My fuel barely makes it out of the tank. It doesn't make it up to the carb at all. Can you explain more about pushing the diaphram? Is it enough just to do it once before trying to start or ??? Thanks

Tony Hallo

Take a small allen wrench and insert in into the vent hole on the regulator, lightly push the diaphram down, this will allow the air trapped in the pump to vent through the needle valves. In your case I would bet the tank is mounted much lower than carb and the pump isn't wet hence the check valves are leaking since they are dry. I would do the following to verify problem, choke on, push diaphragm down while cranking, pump gas? Yes continue and attempt start, no, your carb is not working, check pump, check pulse line, check for leaks.
Alternate procedure, take a small section of hose and pressurize the fuel tank by blowing, some may not like this, press the diaphragm while maintaing pressure, fuel should flow into the carb. Yes attempt start, no, something is wrong in the carb.

easyschnucki

My Feedback: (2)

That happend to me too till I blew some air in the overflow (vent line). Gasoline shot immediately up to the carb. Maybe there's was an air pocket or so?? Today I had it running the 2nd time for about 5 min, totaling 7min so far. Takes about 10 flips or so with choke closed then it fires 1 time, sometimes with a nice flame out of the muffler !!! Choke open and a bit throttle combined with a few more flips and she comes. Needles are still on factory setting. Takes gas nicely

kwik

rcgood,

I have the same problem with my ZDZ 90 every time its a few days, maybe a week or two, since last time it was run.

Does not want to pump. I shoot a bit gas straight into the carb, and flip it. It ignites, and from then on all is okay.

My tank is mounted faaaar higher than the carb.