[wacio]

My advice is to buy rebuild kit. The seal under the valve handle is getting hard and the valve starts leaking. It first leaks thru - meaning that the gas will continue sipping into the carb continuously. This will be causing gunk buildup in the jets. So even if the valve doesn't appear to leak externally - I'd replace if older than 10 years. I bought few of those cheap petcocks you can get on eBay - the problem is that most don't fit - collide with seam on the tank or end up needing to operate handle backwards. Most of them are on, off, reserve - not vacuum operated - so you need to remember to turn off.