Author Topic: Overfilled Gas Tank=rough running?  (Read 1498 times)

Offline xsv

  • Jr. Member
  • **
  • Posts: 81
Overfilled Gas Tank=rough running?
« on: May 27, 2012, 04:30:12 pm »
Today I pulled into the gas station as the fuel tank supply truck was leaving.  I topped off the tank into the gas tank neck.  (Leaving on a 3200 mile ride shortly)  A minute later I am driving at 60 mph with the cruise control on and the bike feels like it is surging.  I have NEVER experienced this surging on the bike.

I ride about 4 miles home and as I pull through the gate the bike almost stalls.  It is running a bit rough and accelerating slowly.

My first inclination was that I got some bad gas.  When I opened the cap to siphon out the gas some of it blew out of the filler neck and onto the tank.  I siphoned it down below the filler neck and now it "seems" just fine.

I removed my CA cannister several years ago to make room for my Rostra.  My recollection was that I when I removed the cannister I looped the two lines together. 

My question is did I eliminate my vent by looping those lines together? Would lack of vent and overfilling cause what I experienced?

The answer seems to be yes and yes.  However, I am just a little wound as I am departing for a 3200 mile ride in about 5 days! :)

Offline CrashGordon

  • Full Member
  • ***
  • Posts: 239
Re: Overfilled Gas Tank=rough running?
« Reply #1 on: May 27, 2012, 05:56:47 pm »
I can tell you that I almost always fill my bike into the neck and I've never had a problem. I do not have a CA bike, so it sounds like something that's different or changed about your bike (like eliminating the vent).

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 480
  • Country: 00
Re: Overfilled Gas Tank=rough running?
« Reply #2 on: May 28, 2012, 11:25:05 am »
Which two lines did you loop together?  If the line leading from the tank to the canister is not open to the atmosphere, you indeed eliminated your vent.  Extend that line downward below your fairings.

Offline xsv

  • Jr. Member
  • **
  • Posts: 81
Re: Overfilled Gas Tank=rough running?
« Reply #3 on: May 28, 2012, 11:32:43 am »
Which two lines did you loop together?  If the line leading from the tank to the canister is not open to the atmosphere, you indeed eliminated your vent.  Extend that line downward below your fairings.

That would be the line :-[

I read another post where someone just attached a mini automotive breather to this line and blocked the other one.  Any harm to just leaving the line open or should a breather be attached?

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 480
  • Country: 00
Re: Overfilled Gas Tank=rough running?
« Reply #4 on: May 28, 2012, 04:01:35 pm »
That would be the line :-[

I read another post where someone just attached a mini automotive breather to this line and blocked the other one.  Any harm to just leaving the line open or should a breather be attached?

I believe the other one goes to the air box.  Block that one. Leave the one from the tank open. Preferably extend it so fuel and vapors clear your fairings but it isn't real critical.

What likely happened is that your tank burped fuel, it went in to the air box and temporarily flooded your engine.

Offline marku8a

  • Full Member
  • ***
  • Posts: 191
  • Country: 00
Re: Overfilled Gas Tank=rough running?
« Reply #5 on: May 28, 2012, 04:36:07 pm »
I read another post where someone just attached a mini automotive breather to this line and blocked the other one.  Any harm to just leaving the line open or should a breather be attached?

That was me.  I removed the hose color coded red and capped the fitting at the tank. The hose color coded blue is the breather hose. I attached a cheep automotive fuel filter to that hose. I really don't think this it necessary and could probably just run the hose to the bottom of the bike.

Mark
2009 C14 Red
Fly_ectomy, K&N Filter, Oxford Heated Grips, PC V, Full Area P Exhaust
How far can a person run into a forest?

Offline xsv

  • Jr. Member
  • **
  • Posts: 81
Re: Overfilled Gas Tank=rough running?
« Reply #6 on: May 28, 2012, 06:28:57 pm »
That was me.  I removed the hose color coded red and capped the fitting at the tank. The hose color coded blue is the breather hose. I attached a cheep automotive fuel filter to that hose. I really don't think this it necessary and could probably just run the hose to the bottom of the bike.

Mark

I think I am going to just follow what you did and remove the separator and all lines.  However, I am going to wait until I come back from my ride aka leave well enough alone for now!

Thanks for the help

Offline stevewfl

  • Arena
  • Hero Member
  • *****
  • Posts: 3843
  • Country: 00
Re: Overfilled Gas Tank=rough running?
« Reply #7 on: May 29, 2012, 10:13:31 pm »
Interesting.
“The World is a book, and those who do not travel read only a page.” St. Augustine

Offline Fretka

  • Full Member
  • ***
  • Posts: 216
  • Country: us
Re: Overfilled Gas Tank=rough running?
« Reply #8 on: May 30, 2012, 10:25:11 am »
If you blocked the vent line to the tank your gas tank is likely to suddenly take on a new shape, picture a plastic bottle evacuated of all air!
Wretched excess visited upon an innocent C-14

Offline maxtog

  • Hero Member
  • *****
  • Posts: 4286
  • Country: us
  • 2011 Silver ABS Concours 1400 (&'09 Infiniti G37S)
Re: Overfilled Gas Tank=rough running?
« Reply #9 on: May 30, 2012, 03:28:13 pm »
If you blocked the vent line to the tank your gas tank is likely to suddenly take on a new shape, picture a plastic bottle evacuated of all air!

I don't think that would happen with a steel gas tank.  It would be more likely that the fuel pump would not be able to overcome the vacuum and then not be able to deliver enough gas and the engine would go very lean and then stop running.
Ghul ECU flash, HID, Canyon Cages front/rear, Helibars risers, Phil's wedges, Grip Puppies, Sargent World seat-low & heated & pod, Muzzy lowering links, Soupy's stand, Nautilus air horn, Admore lightbar, Ronnie's highway pegs, front running lights, helmet locks, Garmin Zumo 450, Throttle Tamer, MRA X-Creen.  Scorpion EXO-1000,  Tourmaster Flex II.

Offline CrashGordon

  • Full Member
  • ***
  • Posts: 239
Re: Overfilled Gas Tank=rough running?
« Reply #10 on: May 31, 2012, 07:44:27 pm »
I don't think that would happen with a steel gas tank.  It would be more likely that the fuel pump would not be able to overcome the vacuum and then not be able to deliver enough gas and the engine would go very lean and then stop running.
Trust me, it can. I had it happen on a Ducati after a dealership mechanic pinched the return line during a service and didn't catch it. It was sudden and very loud.

Offline maxtog

  • Hero Member
  • *****
  • Posts: 4286
  • Country: us
  • 2011 Silver ABS Concours 1400 (&'09 Infiniti G37S)
Re: Overfilled Gas Tank=rough running?
« Reply #11 on: May 31, 2012, 07:57:52 pm »
Trust me, it can. I had it happen on a Ducati after a dealership mechanic pinched the return line during a service and didn't catch it. It was sudden and very loud.

Wow!  I just would not have believed the fuel pump could be that powerful and all the seals that strong!
Ghul ECU flash, HID, Canyon Cages front/rear, Helibars risers, Phil's wedges, Grip Puppies, Sargent World seat-low & heated & pod, Muzzy lowering links, Soupy's stand, Nautilus air horn, Admore lightbar, Ronnie's highway pegs, front running lights, helmet locks, Garmin Zumo 450, Throttle Tamer, MRA X-Creen.  Scorpion EXO-1000,  Tourmaster Flex II.

Offline CrashGordon

  • Full Member
  • ***
  • Posts: 239
Re: Overfilled Gas Tank=rough running?
« Reply #12 on: June 01, 2012, 06:17:41 am »
Yep, the top of the tank buckled down about 2 inches. I was riding and heard a loud pop. Stopped and didn't see anything right off, but headed to the house. When I got home and picked up my tankbag, holy s&$t! It looked like someone took a swing at my tank with a sledgehammer. Dealer didn't argue since it was about 3 days after the 600 mile service, but it did take a few weeks to get a new tank from Italy.

Offline Rawman

  • Full Member
  • ***
  • Posts: 154
  • Country: us
Re: Overfilled Gas Tank=rough running?
« Reply #13 on: June 01, 2012, 07:54:15 am »
Yes, the gas tanks can "implode".  There were a few pics on our old site that showed this was a very real occurence.
2009 Non-ABS
VStream, PR2s, AreaP Full Exhaust, Carbon Can, PC-V, BMC Air Filter, 151 Dyno'd RWhp.
'04 Honda VTX-1300C, '01 Kawasaki ZRX-1200R, '87 Yamaha VMax, '79 Kawasaki K-1000 LTD, '77 Kawasaki KZ-1000,'80 Suzuki GS-550L

Offline Mister Tee

  • Full Member
  • ***
  • Posts: 480
  • Country: 00
Re: Overfilled Gas Tank=rough running?
« Reply #14 on: June 01, 2012, 11:37:10 am »
Yep, the top of the tank buckled down about 2 inches. I was riding and heard a loud pop. Stopped and didn't see anything right off, but headed to the house. When I got home and picked up my tankbag, holy s&$t! It looked like someone took a swing at my tank with a sledgehammer. Dealer didn't argue since it was about 3 days after the 600 mile service, but it did take a few weeks to get a new tank from Italy.

What you SHOULD have done is saved that old tank, and sold it over Craigslist as a "pro stunna tank."  Pro stunnas deliberately bash the top of the tank to turn it in to a seat, for high chair wheelies.