Author Topic: Honey, do you smell gas? CX500 fuel leak  (Read 2732 times)

0 Members and 1 Guest are viewing this topic.

Offline snarferer

  • Full Member
  • *
  • Posts: 68
Honey, do you smell gas? CX500 fuel leak
« on: July 28, 2008, 02:50:40 PM »
So I was sitting out on my porch and I thought I smelled some gas.  It was very faint and I thought I was just dreaming about riding my motorcycle.  However, when I went into the garage, I noticed i GIANT pool of gasoline (half a liter or so) on the garage floor.  I panicked, because my cb350f's carbs leak a little but.  But it was coming from under my girlfriend's bike. 
She has an 85ish cx500.  It has never leaked gas before.  When i shut off her fuel petcock, the gas stopped leaking.  Can I assume this is a carb float sticking issue, but really bad?  Might it be another issue?

Offline mattcb350f

  • Hardly a
  • Master
  • *****
  • Posts: 1,625
  • 1974 CB350F
Re: Honey, do you smell gas? CX500 fuel leak
« Reply #1 on: July 28, 2008, 02:56:18 PM »
Probably just a stuck float. I never leave a bike with the fuel left on for that reason. The floats can just get hung up sometimes.

I would take it for a ride and then park it again. Leave the gas on and watch it carefully. If it's stopped than no problem. if it keeps leaking than the carbs need some work. sometimes a lil' tap with the back end of a screwdriver can seat them too.

But if the bike runs well than I wouldn't bother, just remember (or ask her politley to remember) to turn the gas off everytime.

 Matt.
1974 CB350F,  1980 CB125S,  1981 XL80S
Non Honda's: 86 & 87 Husqvarna 400wr's

My CB350F resto: http://forums.sohc4.net/index.php?topic=30467.0
Gallery at:
http://gallery.sohc4.net/main.php?g2_itemId=298318

Offline TwoTired

  • Really Old Timer ...
  • *******
  • Posts: 21,805
Re: Honey, do you smell gas? CX500 fuel leak
« Reply #2 on: July 28, 2008, 04:20:37 PM »
The usual suspects are the same as for the SOHC4.

Fuel contamination blocking the float valve.
Bad float valve/seat.
Float sticking, Hinge pin, carb body to the float frame friction.

Cracked stand pipe.

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline crazypj

  • I'm brill, me
  • Old Timer
  • ******
  • Posts: 4,467
  • first 100,000 miles. 1977 CB550F
Re: Honey, do you smell gas? CX500 fuel leak
« Reply #3 on: August 01, 2008, 02:06:43 AM »
There is also a possibility that the 10% ethanol gas now sold  has soaked into float and made it sink. May need to get later model float.
PJ
I fake being smart pretty good
'you can take my word for it or argue until you find out I'm right'

Offline Uncle Ernie

  • Old Timer
  • ******
  • Posts: 3,613
Re: Honey, do you smell gas? CX500 fuel leak
« Reply #4 on: August 01, 2008, 04:40:54 AM »
Always always always turn the gas off.  I turn the gas off before i park, just to run a little out- especially a good idea on old Beemers.

BEFORE you start the bike;
1) take the plugs out and turn it over a couple of times to see if any gas comes out of the plug holes.  If there is gas in there, liquids don't compress and you may do damge. 
2)  Smell your oil to see if gas got past the rings and into the crankcase.  You may need to change the oil.
Dude- your 8 layers are showing!

fixahonda

  • Guest
Re: Honey, do you smell gas? CX500 fuel leak
« Reply #5 on: August 02, 2008, 05:38:05 PM »
If I don't run my 350F for a few days it will leak gas out of the overflows when I turn the petcock on. I don't know why. I'm sure it's one of the myriad reasons that have already been stated, either that or it just likes to annoy me (probably this).

I haven't bothered to take it apart and see. It runs perfectly otherwise.

I just keep a screwdriver handy and give them a preemptive tap when I turn the fuel on. Maybe your girlfriends bike is starting to get cranky like mine.