Continued from this URL Walbro Carb WT-669
I wrote this to JasonB after reading the above post. I am still having problems with this Walbro card.
I saw your post on setting the high and low side of this carb. This thing is driving me nuts. I pulled the fuel lines from it last winter and found that was NOT the thing to do. This summer it would never prime right and wanted to run on choke only. Well I rebuilt the carb, made sure the exhaust was not plugged and started again. Like at the start however it only seems to want to prime if I point the weedeater straight up. Once primed it seems to stay in fuel. The in tank filter seems to be fine. The lines look good. So I ground around the adjustment screws and tried what you said. About 1.5 to 2 out it will start full choked but only idle for about 25 seconds. I have tried to fine adjustment in that range but can never get any better than that. This is all with new fuel I forgot to add. I saw someone say they pulled the adjustment screws completely out and cleaned the ports. Does that need to be done. That is the only thing I have
not done that I can think of.
Here were a few suggestions from JasonB to catch us up. That I might have possibly swapped the lines to the carb. They are different size. The small tube is the incoming fuel line that is tied to the filter. The larger line has no line in the tank and just ends were it enters the tank. As you prime it cycles gas from the tank through the carb pushing the air out the larger line.
He also wondered if maybe the incoming line might have a hole in it. I did too. Once the carb is primed I never see air in that line. Also when I prime into that like it blows bubbles out the filter only. It does act like the old 6lb pressure fuel pump on a old chevy sucking air through a bad fuel line but I dont think that is it.