Leaking Gas From Blower

Old 07-25-18, 08:50 PM
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Leaking Gas From Blower

I own since new a old Stihl BG72. Runs perfectly. Recently it has developed a habit of the tank getting pressurized and thus leaking out one of the carb hose connections. The leak is extremely minor, more of a layer of fuel that eventually covers everything. Never did this before in all environmental conditions (20+years).

So my question is do older small engine carbs (Walbro) have some type of vent mechanism for relieving pressurized tanks? I wouldn't think so as I think then gas could flow out which would be bad but not sure. I'm not talking about a inlet vent in the cap to prevent vacuum which they require. Or do the caps also have a "relief" vent built in to prevent excess pressurization which would only activate when too much pressure builds up? (Again probably bad idea because of the possibility of discharging gas)

If not, how do all these small engines not leak everywhere when the tanks get warm? My lawn mower, chainsaw, tree trimmer don't leak. I'll probably first look into replacing the hose connections as maybe they are starting to get too "loose" on the nipple inlet, though they have been replaced before for maintenance.
Old 07-26-18, 12:20 AM
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They just hold a little pressure without leaking. If you have a leak under slight pressure, then you have a place that needs repair.

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