026 spitting gas out of carb

[fossil]

My Stihl 026 is spitting gas out of the carb. The carb is a Walbro WT 194. I can just barely get it fired by holding the throttle open. Needless to say it's running a little rich. Both needles set to 1 turn out. Any idea what's going on?

Any help would be appreciated.

Tim

 

[Adirondackstihl]

Metering lever set too high more than likely.
Spark screen may be plugged too?

 

[fossil]

Metering lever set too high more than likely.
Spark screen may be plugged too?

It's not the spark screen as it's not in there. I will pull the carb apart and then ask how to set the lever.

Thanks

 

[blsnelling]

Pump diaphragm and gasket in the wrong order? The gasket goes against the body, then the diaphragm.

 

[ELECT6845]

026

Did you check compression?
Low compression can cause them to spit back

 

[Somesawguy]

It does that if you take the filter off.

Check the Impulse line for cracks.

 

[hotshot]

Pump diaphragm and gasket in the wrong order? The gasket goes against the body, then the diaphragm.

I think Brad is jacking with you, the fuel pump diaphragm goes on first against the carb body, then the gasket, then the cover on a WT-194 Walbro.

 

[blsnelling]

Is the diaphragm that touches the needle lever not the pump diaphragm? That's the side I'm referring to.

 

[Adirondackstihl]

Metering Side
Gasket....metering diaphragm....cover

Pump Side
Pump diaphragm....gasket....cover

 

[hotshot]

Other side, that's the metering diaphragm & it is installed gasket first over there...

 

[Adirondackstihl]

Is the diaphragm that touches the needle lever not the pump diaphragm? That's the side I'm referring to.

Often mistaken as such, however no. The side you mention is the metering side.

 

[Zippy]

Metering side - gasket on carb body, then diaphragm with metal disk with button that pushes metering lever

Pump side - diaphragm with flaps on carb body then one or two gaskets on top and then the top cover

 

[blsnelling]

Won't be the last time I'm wrong. I'll go sit in the corner now

 

[Adirondackstihl]

Metering Side

Pump Side

 

[fossil]

Impulse line is OK . Holds 10 psi no leaks. Compression >160 psi. Piston looks good and clean.

The metering gasket / diaphram assembled with gasket against the carb body then the diaphram and then the cover.

On the fuel pump side there is a gasket against the cover and a tan colored mylar diaphram????? There is no fibre washer under the screw head.

I will upload a few pics in a bit.

I did have the air filter off when it was spitting gas.

 

[Zippy]

You could check the metering lever is set to the right height - it's should be about 1.5mm below a straight edge across the carb body, or most likely there's some shoulders around the lever and it should be flush to that.

Then you could rebuild it, connect the fuel line to a pressure tester and put about 7psi on it and see if the metering needle is holding pressure. If not then it could be a cause of flooding.

 

[fossil]

Here's the parts I have on the pump side.

Here's the metering side. Does it look correctly assembled from what you can see?

I will check the height.

 

[Zippy]

Looks good to me

On the metering side (with the lever) you put the gasket on the body then the diaphragm with the button on then the top is screwed on.

Then try pressure testing it at around 7psi - shouldn't lose any pressure at all.

 

[fossil]

The metering lever is dead flush with the ridges around it.

Another question. The fuel line looks complete and like a Stihl line but it's short. I can can only get the base of the fuel filter about 1/2 inch from the tank filler hole. Does that seem right? If it does, that filter is going to be tough to change.

 

[Zippy]

Sounds a bit short to me but I haven't got an 026 so best let somebody who has answer.

Does the filter rest on the bottom of the tank ok when the saw is the right way up - if yes then I guess it's ok.