Cold start fuel leak

[aspen874]

The bike is a 2010 Bulldog Bagger which is fuel injected. The fuel leak is on the end of the fuel line where it connects to the throttle body intake right where the clamp is. It leaks significantly on the first start of the day, the rest of the time it does not leak at all.

I have checked the line as best I can, it seems secure and I can't see any obvious reason for the leak, anyone have any ideas.

 

[Sven]

I'm going to take a guess at an idea and say it's a generic car type hose and connector end? Where one design you collapse both plastic locking tabs to go into the connector. With a limited twist and pull at the same time to pop it off? On the fuel pump outlet side is a tube with a rounded flair end ? Inside the hose connector itself is an oring maybe? That oring slides over the bulge type hump on that tube. The rubber is relaxed and slightly shrunk. The fuel pressure wants to blow that hose right off the tube. So I'm suspecting the movement IS the hose's oring. And when the pressure is filling up the hose, it is going to push fuel out of the static position the oring is in. Then the force of the hose is going to compress the oring up against the connector's oring it's stationed in. The oring starts to squish itself against the connector and tube bulge. It has nowhere to go but stop the leak on the [pressured] crush. Can't be a cut oring or it would still leak from that pressure. My guess is the rubber shrunk enough that the static pressure of the oring can't hold fuel back from the first moment of pressure.

Okay, I reread the OP's post and I was at the wrong end of the hose, but the same idea applies to this mirrored end of the hose asswell.

 

[pknowles]

Replace the hose and clamp. As Sven said, they are an automotive type clamp. It would have been nice if they would have used the quick disconnect like the harley ones.

 

[aspen874]

thank you both, I will replace the hose and clamp and report back

 

[Jersey Big Mike]

thank you both, I will replace the hose and clamp and report back

Both my K-9's have done this after time -- the end of the line cracks -- replace it and all should be good for a while.

 

[geoffmt]

My 2008 Bulldog did that,if the bike sat for longer than a week.The hose would dry out the clamps couldn't be tightened. I just replaced the lines and clamps. all is good for 2 years now.