Rebuilding a Walbro carb

[Mark Corbelli]

I am in the process of trying to get a 31cc engine on an old cultivator running. It uses a Walbro carb. I haven't been able to get it running properly. I have taken the carb apart, soaked it in cleaner, blown out all the channels with compressed air, and replaced the parts that come with the rebuild kit. I can get it to run, but I'm not having any luck adjusting the low and high speed idles to get this to run without stalling out. I checked the muffler to make sure it's clear and there are no screens that I can see, just a straight path to the outside. I have noticed that every time I leave it for awhile, when I come back there is gas in the cylinder and I must take out the spark plug and drain it and dry the spark plug before I begin again. I took off the gas tank and checked the two fuel lines and they look fine. Is this normal? What would make the fuel leak into the cylinder when not in use? I replaced everything inside, at least I think so. The rebuild kit was universal, so there were a few parts left over. There were two aluminum discs and a screen I didn't use because the ones in the carb were in there in such a way as I couldn't figure out how to get them out. Otherwise, everything that matched up with the kit was changed out.

[Artemis]

Start with the low and high needles at 1-1/4 turns. Get it running and keep it going for about a minute. Then start with the low speed adjustment. Turn it in very slowly and find the point at which it runs at the highest idle. At this point it should die out when trying to accelerate. Turn the low speed needle out slowly until you can hit the throttle and it accelerates without hesitation. Now you can move on the high speed adjustment. Run it at full throttle and slowly turn the high speed needle in/out to find the point at which it is running at the highest rpms. At this point it will sound good and run well but not have much power under a load. With it running at full throttle back the high speed needle out slowly until the engine just starts to falter and miss. That's where you want to leave it. It should now accelerate quickly and when put under a load it should sound smooth

I checked

How can you tell there is gas in the cylinder? Is it full?

No that is not normal. There is an inlet valve in the carb that is leaking, it's either not adjusted correctly or there is trash keeping it from sealing.

[m_corbelli]

Thank you for your input.

The carb sits in a circular plastic housing that has a plate the attaches over it that also has the choke, medium, run knob. I have this plate off while I'm trying to work on the carb. If this thing sits overnight, there will be several tablespoons of fuel trapped in this plastic housing. It has to be leaking out the carb. Some of the gas is leaking into the cylinder also, because if I take out the plug before even trying to start it, the plug is wet and about a teaspoon of has drips out the spark plug hole. I'd like to know more about a stuck valve and how I can clear it.

[Artemis]

The inlet valve in the carb is leaking. Could be trash or not adjusted correctly. What model Walbro carb is it?

[Mark Corbelli]

[m_corbelli]

Art:

I found the following numbers on the carb:

W1149A J9

Can you help me?

Mark

[luvsmengines]