MOTOBRICK.COM

TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Motorhobo on October 06, 2014, 11:10:42 AM

Title: Fuel leaks from rear outlet nipple when disconnected
Post by: Motorhobo on October 06, 2014, 11:10:42 AM: This is why I try not to work on my bike too much, because every time I touch it, weird things happen.

I seem to remember that when you disconnect the fuel hose leading to the fuel rail, the fuel discharge from the rear outlet nipple stops after a couple seconds. For me just now, it didn't stop but just continued to flow and a constant rate, more than dripping but not completely unobstructed, so maybe 1/10 of what the unobstructed flow would be from a hole that size. What's up with that? I thought nothing could escape there unless the fuel pump was running -- maybe the pump isn't fully connected to the line leading to that nipple, or it's coming disconnected from the nipple or...? At any rate, how could that affect the running of the bike? If that line is pressurized and something is escaping, then the bike isn't getting the fuel pressure it expects, or?
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: Motorhobo on October 06, 2014, 11:34:19 AM: I guess it's just a WTF kind of day.

I found a short piece of hose, capped it off, plugged the nipple, pulled the tank, came back 20 minutes later and the flow had stopped.

So all I can say is, when you pull the tank best have a funnel and a container handy because I lost at least 250ml of fuel before it stopped leaking.
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: roninvt on October 06, 2014, 04:32:18 PM: Hi Motorhobo,

I have pulled the tank off both of my bikes and I only get a dribble, that is easily managed by a rag.
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: Motorhobo on October 06, 2014, 05:44:14 PM: Quote from: roninvt on October 06, 2014, 04:32:18 PM
Hi Motorhobo,

I have pulled the tank off both of my bikes and I only get a dribble, that is easily managed by a rag.

Me too -- many times, but today was different, that's why I posted this -- I don't know why I got a steady flow today, it's out of the ordinary enough to pose the question as to why it might have happened. Does anyone have a possible explanation? I rode the bike 60 miles today and it behaved normally so whatever the reason it doesn't appear to be affecting fuel delivery or pressure.
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: Scott_ on October 07, 2014, 11:11:00 PM: Maybe the question should be, how long after you shut the bike off did you wait before you took the lines apart.
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: Motorhobo on October 08, 2014, 05:28:41 AM: Good question... I think it had been standing for quite a while...but I can't say for sure that I didn't make a brief crank attempt in the minutes before pulling the hose.
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: orforester on October 08, 2014, 11:06:17 AM: I pulled mine off yesterday and a similar thing happened, but it always does, not a stream but somewhat steady. More than a drip, but less than stream. Also happens as you move the tank around. I just wear old shoes! My wife calls me old gasy?
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: Inge K. on October 08, 2014, 11:52:52 AM: Remove the fuel pump fuse, start the bike to empty the system........less mess, when disconnecting the pressure hose.
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: frodef on October 08, 2014, 01:48:57 PM: Isn't it easier to just disconnect the electrical connector for the tank?
Title: Re: Fuel leaks from rear outlet nipple when disconnected
Post by: Motorhobo on October 09, 2014, 05:36:27 AM: Personally, I'd rather pull a fuse. The fewer times I touch the connectors on my 20 year old moto the better. I only touch the connector if I absolutely must remove the tank.