Small Engines (Lawn Mowers, etc.): Briggs & Strat 6hp wont stay running, surface tension of water, gummie bear

Question
Hi,

Not really a question but some information regarding Briggs & Strat 6hp motors that will start but won't continue to run.  Mine is on a Sears model.   I see a lot of postings on this topic and I've just solved the same problem so I thought I would share my experience.

Symptom- Prime, pull the cord, mower would run for about two seconds and die.  Same thing over and over.

1.  I first cleaned the old carb without luck.
2.  Replaced the carb with a new one from Sears and it ran fine for two weeks and then it was back to the original symptom.
3.  I replaced the fuel line because it was really kind of soft and distorted.  Probably should have done that when I replaced the carb but oh well.
4.  Still would not run more than a few seconds.
5.  Pull off the float bowl and saw small black specks.   Clean the bowl, blew out the jets in the bolt that holds the fuel bowl on, and put the bowl back on.
6.  Started right up.

My guess - deteriorating fuel hose was causing the jets to clog.


Answer
You got it, I would have to agree with you. Whenever I work on a carb the fuel tank allways gets cleaned. If the fuel line is cracked and brittle on the outside its probably coming apart on the inside too. Sometimes a fuel line feels like a gummie bear when you pinch it because the gas is actually melting the hose away from the inside out. Carburetors use small pinholes to regulate the gas flow. As you found out doesnt take much to clog one up. Even a thimble full of water from condensation in a tank can clog it up due to the surface tension of water. Gas does not have this property. Thanks for sharing your diagnosis. Happy mowing.