Gas Tank Petcock Problem?

jboyd12 · March 28th, 2012, 05:54 PM

Does your gas tank flow gas when its on ON? When its on PRI it flows abundantly but not in the ON position... Could this be causing a problem? Thanks

k-os · March 28th, 2012, 05:58 PM

The petcock is vacuum operated. When the petcock is set to ON, but the bike isn't running it won't flow because there is no vacuum. When it's set to PRIME it has open flow.

MikeBudd · March 28th, 2012, 07:11 PM

Yea, if it's flowing in the on position, something is wrong with your petcock.

Slono · March 28th, 2012, 07:35 PM

Mine drips a lot even when its put on the "ON" position... I think if you're not careful and the gas sloshes around in the tank it disturbs the vacuum and ruins the suction. Also if you put a tank in a place where the ambient temperature is higher than where you had your bike, the gas expands and destroys the vacuum as well. I had both of these happen to me. You have to be really careful when taking off your tank otherwise it'll leak even when its "ON".

CZroe · March 29th, 2012, 02:40 AM

Lots of reports of a manufacturing defect in the petcock (circular nylon seal is C-shaped instead). It'll leak even when turned off.

nickjpass · March 29th, 2012, 06:30 AM

Nope, mine doesn't.

ForceofWill · March 29th, 2012, 06:46 AM

Like others said, it's not supposed to flow in the ON position with the bike off. Mine does however and it's a pretty common problem.

cbdallas · March 29th, 2012, 06:49 AM

In some cases, it could be dirt vs. a defect. The petcock on my Virago leaked when 'on' so I took it apart, cleaned the diaphragm with carb cleaner & a Q-Tip, cleaned the inside of the housing, put it back together and it worked perfectly.

GateKeeper · March 29th, 2012, 02:38 PM

if it leaks, and allows gas to flow, you can end up overflowing your carbs, you will then get gas into the engine, it will then mix with your oil, and you will then have more issues than you will care to have.

get it fixed or replaced

alex.s · March 29th, 2012, 02:40 PM

Quote:

Originally Posted by GateKeeper

if it leaks, and allows gas to flow, you can end up overflowing your carbs, you will then get gas into the engine, it will then mix with your oil, and you will then have more issues than you will care to have.

get it fixed or replaced

the floats are still valved. how does the gas mix with the oil? by being in the firing cylinder? gas normally goes in there, doesnt it?

Slono · March 29th, 2012, 02:47 PM

Quote:

Originally Posted by GateKeeper

if it leaks, and allows gas to flow, you can end up overflowing your carbs, you will then get gas into the engine, it will then mix with your oil, and you will then have more issues than you will care to have.

get it fixed or replaced

Who else has a leaky petcock problem? Is this a serious problem?

GateKeeper · March 29th, 2012, 03:07 PM

Petcock doesn't fully shut off gas as designed..the carbs fill up and slowly the gas trickles into the cylinders and seeps past the rings and into the crankcase

or

The other possibility is of course that there's a leak in the petcock diapragm and the fuel is being sent directly down the vacuum line

Slono · March 29th, 2012, 03:47 PM

So... Isn't this a major recall situation if so many people have this problem? My ninja was brand new when I got it and I've made sure I've taken care of it well. It seems like many other people have the same issue.

GateKeeper · March 29th, 2012, 04:22 PM

this post touches upon possible petcock issues as well as other things

http://www.ninjette.org/forums/showthread.php?t=99501

recall maybe not, but check and make sure your petcock is not leaking, if it is take it in to get it fixed or try to do it on your own, they should not leak or flow gas unless in Prime, or ON and Vacuum is applied

Slono · March 29th, 2012, 04:33 PM

I'm confused... There's a hole on the side of the gas tank that leaks. This isn't the petcock fault is it? My petcock doesn't leak, but the side holes do.

cbdallas · April 2nd, 2012, 08:28 AM

I don't think there's any good reason to have holes in the sides of a new-gen tank. I know a lot of people screwed up the old-gen tanks by using the wrong fairing bolts, but I don't recall that being a new-gen design issue. If gas is leaking from the sides of your tank, you have a problem. Post a picture of these holes.

Slono · April 2nd, 2012, 08:47 AM

Quote:

Originally Posted by cbdallas

I don't think there's any good reason to have holes in the sides of a new-gen tank. I know a lot of people screwed up the old-gen tanks by using the wrong fairing bolts, but I don't recall that being a new-gen design issue. If gas is leaking from the sides of your tank, you have a problem. Post a picture of these holes.

Its this hole here... My tank actually has two holes in this area and both hoses are attached to a plastic reservoir of some sort.

cbdallas · April 2nd, 2012, 09:15 AM

I believe those are specific to California-emissions bikes and are unrelated to the petcock. I guess Canada mandates them as well? They basically run gasoline fumes through a charcoal canister, although I don't think they're supposed to have liquid fuel running through them, as that essentially ruins the charcoal.

March 29th, 2012, 06:30 AM	#6
nickjpass #squid Name: nickypoo Location: Five Guys Join Date: Jul 2011 Motorcycle(s): Track dedicated 2008 ZX6R Posts: A lot. MOTM - Jul '16	Nope, mine doesn't. __________________________________________________

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March 28th, 2012, 05:58 PM	#2
k-os ninjette.org sage Name: Andy Location: Sheboygan, WI Join Date: Dec 2008 Motorcycle(s): 1988 Honda Hawk NT650, 1989 Honda Hawk NT650, 1997 GSXR750 Track Bike Posts: 890	The petcock is vacuum operated. When the petcock is set to ON, but the bike isn't running it won't flow because there is no vacuum. When it's set to PRIME it has open flow.

March 28th, 2012, 07:11 PM	#3
MikeBudd ninjette.org guru Name: Mike Location: Vancouver, British Columbia Join Date: Aug 2011 Motorcycle(s): RED 2010 Ninja 250r Posts: 304	Yea, if it's flowing in the on position, something is wrong with your petcock.

March 28th, 2012, 07:35 PM	#4
Slono ninjette.org guru Name: Solon Location: Toronto, Ontario Join Date: Jun 2011 Motorcycle(s): 2011 Kawasaki Ninja 250R (sold), 2007 SV650s (deer wrecked), 2010 Suzuki SV650S Posts: 334	Mine drips a lot even when its put on the "ON" position... I think if you're not careful and the gas sloshes around in the tank it disturbs the vacuum and ruins the suction. Also if you put a tank in a place where the ambient temperature is higher than where you had your bike, the gas expands and destroys the vacuum as well. I had both of these happen to me. You have to be really careful when taking off your tank otherwise it'll leak even when its "ON".

March 29th, 2012, 02:40 AM	#5
CZroe CPT Falcon Name: J.Emmett Turner Location: Newnan, GA Join Date: Apr 2009 Motorcycle(s): '08 CP Blue EX250J, '97 unpainted EX250F, 2nd '97 unpainted EX250F (no engine), '07 black EX250F Posts: A lot.	Lots of reports of a manufacturing defect in the petcock (circular nylon seal is C-shaped instead). It'll leak even when turned off.

March 29th, 2012, 06:46 AM	#7
ForceofWill Blind 250 Loving Whore Name: Tom Location: Chesapeake, VA Join Date: May 2011 Motorcycle(s): 2008 250R, 02 FZ1, '20 Fat Bob 114 Posts: A lot.	Like others said, it's not supposed to flow in the ON position with the bike off. Mine does however and it's a pretty common problem.

March 29th, 2012, 06:49 AM	#8
cbdallas ninjette.org guru Name: Charlie Location: Wylie, TX Join Date: Nov 2011 Motorcycle(s): 2007 Ninja 650R Posts: 317	In some cases, it could be dirt vs. a defect. The petcock on my Virago leaked when 'on' so I took it apart, cleaned the diaphragm with carb cleaner & a Q-Tip, cleaned the inside of the housing, put it back together and it worked perfectly.

March 29th, 2012, 02:38 PM	#9
GateKeeper ninjette.org member Name: Dan Location: Mississauga Join Date: Oct 2011 Motorcycle(s): 250 Ninja - Soon Posts: 96	if it leaks, and allows gas to flow, you can end up overflowing your carbs, you will then get gas into the engine, it will then mix with your oil, and you will then have more issues than you will care to have. get it fixed or replaced

March 29th, 2012, 03:07 PM	#12
GateKeeper ninjette.org member Name: Dan Location: Mississauga Join Date: Oct 2011 Motorcycle(s): 250 Ninja - Soon Posts: 96	Petcock doesn't fully shut off gas as designed..the carbs fill up and slowly the gas trickles into the cylinders and seeps past the rings and into the crankcase or The other possibility is of course that there's a leak in the petcock diapragm and the fuel is being sent directly down the vacuum line

March 29th, 2012, 03:47 PM	#13
Slono ninjette.org guru Name: Solon Location: Toronto, Ontario Join Date: Jun 2011 Motorcycle(s): 2011 Kawasaki Ninja 250R (sold), 2007 SV650s (deer wrecked), 2010 Suzuki SV650S Posts: 334	So... Isn't this a major recall situation if so many people have this problem? My ninja was brand new when I got it and I've made sure I've taken care of it well. It seems like many other people have the same issue.

March 29th, 2012, 04:22 PM	#14
GateKeeper ninjette.org member Name: Dan Location: Mississauga Join Date: Oct 2011 Motorcycle(s): 250 Ninja - Soon Posts: 96	this post touches upon possible petcock issues as well as other things http://www.ninjette.org/forums/showthread.php?t=99501 recall maybe not, but check and make sure your petcock is not leaking, if it is take it in to get it fixed or try to do it on your own, they should not leak or flow gas unless in Prime, or ON and Vacuum is applied

March 29th, 2012, 04:33 PM	#15
Slono ninjette.org guru Name: Solon Location: Toronto, Ontario Join Date: Jun 2011 Motorcycle(s): 2011 Kawasaki Ninja 250R (sold), 2007 SV650s (deer wrecked), 2010 Suzuki SV650S Posts: 334	I'm confused... There's a hole on the side of the gas tank that leaks. This isn't the petcock fault is it? My petcock doesn't leak, but the side holes do.

April 2nd, 2012, 08:28 AM	#16
cbdallas ninjette.org guru Name: Charlie Location: Wylie, TX Join Date: Nov 2011 Motorcycle(s): 2007 Ninja 650R Posts: 317	I don't think there's any good reason to have holes in the sides of a new-gen tank. I know a lot of people screwed up the old-gen tanks by using the wrong fairing bolts, but I don't recall that being a new-gen design issue. If gas is leaking from the sides of your tank, you have a problem. Post a picture of these holes.

April 2nd, 2012, 09:15 AM	#18
cbdallas ninjette.org guru Name: Charlie Location: Wylie, TX Join Date: Nov 2011 Motorcycle(s): 2007 Ninja 650R Posts: 317	I believe those are specific to California-emissions bikes and are unrelated to the petcock. I guess Canada mandates them as well? They basically run gasoline fumes through a charcoal canister, although I don't think they're supposed to have liquid fuel running through them, as that essentially ruins the charcoal.