5

I've got a small engine (11 HP B&S) that has a gravity-fed fuel system, i.e. there is no fuel pump, simply a fuel line between the carburetor and the fuel tank. If I look at the short (~2-3") piece of transparent fuel line between the filter and the carburetor, I can see bubbles (rather large ones, maybe 1/2 the diameter of the fuel line) traveling from the filter into the carburetor.

Is this an indication of a leak in the line, the filter, or one of the connections? Should I be concerned, or is this normal?

I'm also experiencing a loss of power when the engine heats up, and I'm wondering if the bubbles could be related...

2

Could be a possible air leak. This affects your mixture, and would likely be the cause of the problem. Have you tried replacing/tightening the clamps on the hose?

  • An air leak in a gravity-fed system? If there were a leak, wouldn't gas leak out, instead of air leaking in? There's no fuel pump here creating a vacuum in the fuel line. – Mark Jun 9 '11 at 15:24
  • Small enough for air, and not fuel. I guess you could be correct though, but doesn't the carburetor create a vacuum? I have never messed with them, but do recall the engine creates a vacuum when it goes in the down stroke. – FossilizedCarlos Jun 11 '11 at 19:34
  • The bubbles we're talking about are definitely large enough to be indicative of a leak big enough for gas to get out. – Mark Jun 13 '11 at 16:16

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.