Stihl 009 Oil Pump

[Mike8149]

My oil pump quit so I replaced the diaphram and it now pumps great but the problem is when I turn the saw off oil seeps out of the output port and puddles under the chassis. I pulled the pump and soaked it in gasoline overnight to no avail. I checked it with a vacuum pump and it holds 20" of vacuum in one direction and doesn't have any in the other. Could excessive pressure in the crankcase be causing this? If so is there a vent that might be clogged?

 

[2wheels]

it has a one way check ball inside the pump housing that is actuated by a pin connected to diapram with pulse from crankcase.

You could open the cap and breath the tank when done. Also check the vent located behind bar attachment point.

 

[Mike8149]

009 Oil Pump

Cool, I didn't know there was a vent behiind the bar attachement point. I'll check this out and report back. Thanks

 

[Mike8149]

I can't find any vent behind the bar attachment point. The only vent I can see is where the oil come out. There are two screws above and two screws below the sprocket and the upper right one has a metal clip attached to it. I removed the screw and clip and the hole extends into the carburetor area. I guess this could be a vent but with the screw in place I can't figure out what purpose it serves. What is the purpose of the hole and metal clip? Can you please give me another try on the vent? Thanks

 

[Mike8149]

Dahhh I found it, under the clip.

I had cleaned it out previously when I overhauled the carb.

I'll try to relieve the pressure with the oil cap. I don't know what else to do.

I have another 009 and it doesn't do this.

Thanks for your help.