# Fuel tank pressurizes with the primer bulb



## Dswensen (Oct 8, 2006)

I have a Craftsman 18" saw (358.350180). When I prime the saw to start it, the primer bulb pressurizes the fuel tank. Saw won't start and fuel leaks everywhere. There must be a vent on the darn tank, but I can't find it. The cap vent is a duckbill, but only lets air in not out. What am I missing?


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## 30yearTech (Sep 14, 2006)

The primer is supposed to circulate fuel through the carburetor. It sucks gas from the tank, through the carburetor into the primer and returns it back to the fuel tank. The only way that it would pump air into the tank, is if there is an air leak somewhere in the carburetor or the line that comes from the carburetor. I would check and make sure the hose from the carburetor to the primer is connected to the carburetor and primer, and that it's not cracked. If air enters the primer, then it could be pumped into the fuel tank. There is not supposed to be a vent to let pressure out of the tank, if there was, fuel could leak out it.


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## Donnny (May 12, 2021)

The primer is suppose to suck gas from tank it obviously is not doing that the air pressure being put in tank is forcing gas out anywhere their is a leak like lines and gas cap if you loosen primer gas will shoot up suction gas line and eject at loose primer. I suspect something is wrong with primer mount base or carb internally.


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