So the other night, im cruising along on the freeway, I had been on for about 2 minutes, going 75~. All of a sudden the bike just DIES. I have to pull over into all of the shaZam! on the side of the freeway, I try cranking it over, nothin. Put it on reserve, nothing, nothing. I could get it to start, and all it would do was sit at 1200 rpm, and I had to hold it at 1/2 throttle to keep it there. I figured that I switched up the lines when I had the tank off and actually ran it out of gas. I walked it backwards about a 1/4 mile, down the offramp and to a gas station. Popped open the tank, and it looked low.. so I filled it up. Seemed to work fine after that.
On the freeway TONIGHT! Cruising along at 75-80, been on the freeway for about 5 minutes, the bike sputters, and then dies. I pull in the clutch and coast along the emergency lane AGAIN (again, didnt pick up anything in the tires luckily) As I am rolling along, I try to start it, in reserve, in ON.. nothing.. finally just do it in PRIME and it works after cranking it for quite a bit. I get off and go to a gas station. The tank is probably about 1/3-1/2 full, no reason for even the main to run out. I put in a gallon and a half and left the petcock on PRIME. After trying to find a way back home besides the freeway, I give up and get back on it. I was on the freeway for 15 + minutes, until i got to an area I was familiar with, and got off. I didnt have any problems with it. I was also noticing a flatspot midrange, and a weak top end.. With the petcock on prime, those dissapeared.
Moral of the story? Trash your stock petcock, and buy an 04 CR250FX (i think, check bikebandit) petcock for $26 from BikeBandit. 2916036-001 is the bikebandit part number.
I will be running my bike on PRIME until I can get that, Its not only a pain in the butt to have these troubles with the unecessary vacuum petcock, its DANGEROUS to have the godddam bike shut off while you are heading down the highway with no warning! :mad:
Although I hadn't had issues with stock petcock I agree it's a PITA ,too much tubes , the main and reserve...and the vacuum hose....blah :mad:
For me taking the tank off and on is the most difficult procedure, never mind replacing shims...
The vacuum is needed to prevent someone forgeting to turn off the fuel, which if they have bad float valves, the carbs will flood the motor.
The problem with the stock petcock is the check valve in the vacuum port. It will turn to goo from gas fumes and will partially or completely block the the vacuum, which is required to operate the diaphram to allow fuel to flow.
when i got my bike ! was missing .. i have the 2 gas line to a splitter
some1 can show me a photo of how is supouse to be . mine looks like a drug user was the mechanic man ..
(http://i117.photobucket.com/albums/o54/DaxFx/motora/Photo0011.jpg)
Quote from: dgyver on July 22, 2007, 06:35:47 AM
The vacuum is needed to prevent someone forgeting to turn off the fuel, which if they have bad float valves, the carbs will flood the motor.
The problem with the stock petcock is the check valve in the vacuum port. It will turn to goo from gas fumes and will partially or completely block the the vacuum, which is required to operate the diaphram to allow fuel to flow.
Thanks. I am aware...
People should just know, either take your stock petcock apart and verify it is in good shape, replace it, or buy a different one.
could simply be the filler cap vents need cleaning
I'm thinking of ditching the frame mounted petcock and making up my own simple reserve system.
Two pipes from the tank, reserve pipe with on / off valve
Two pipes joined with t connector
single exit pipe with master on / off fuel valve
single pipe connected to carbs t.
lol @ ""drug user was the mechanic man.
yes .. me !!!!
I like the look of the CRF250 fuel tap - and I am also having a similar fuel starvation problem on my '89, which was also laid up a while before I got it, with old gas in the tank. It ticks over fine but bogs down when I open the throttle out on the road. I drained it and put in fresh gas, and checked the tank gas cap for blockages.
The CRF fuel tap is $21.21 at Powersports Pro, by the way. But I don't see a vacuum line connection on it, so do you just tie that tube off and ignore it? Does it just run as a gravity feed tap instead?
Quote from: simoniz on July 31, 2007, 06:49:25 PM
I like the look of the CRF250 fuel tap - and I am also having a similar fuel starvation problem on my '89, which was also laid up a while before I got it, with old gas in the tank. It ticks over fine but bogs down when I open the throttle out on the road. I drained it and put in fresh gas, and checked the tank gas cap for blockages.
The CRF fuel tap is $21.21 at Powersports Pro, by the way. But I don't see a vacuum line connection on it, so do you just tie that tube off and ignore it? Does it just run as a gravity feed tap instead?
Yeah, it's a gravity feed. Also, if your bike was laid up for awhile, just changing the gas won't be enough. You'll need to clean the carbs, that should help a good bit with your bogging issue.
i left my bike sitting for 9 months, twice in the space of 2 years ,. , When i got banned . and i started her. after fresh fuel , worked fine . i dont seem to get these problems ,never had fuel stavation , 1996 , must be the good model :thumb:
Thanks for the quick answer. The previous owner (who runs lots of classic bikes) said he cleaned the carbs before I got it, but I will do them myself again to be sure. That Honda gas tap is a bargain too, and the stock one is a total PITA, as has been noted here!
When eliminating the vacuum, you will need to cap the line or the tee. Otherwise you will be sucking in additional air into the left carb.
Quote from: dgyver on July 31, 2007, 07:04:04 PM
When eliminating the vacuum, you will need to cap the line or the tee. Otherwise you will be sucking in additional air into the left carb.
I can do that! Thanks for the tip.
My CRF Petcock should be here soon, FINALLY.
The stock one has left me stranded countless times. No more. :nono:
Quote from: slowinthestraights on July 31, 2007, 07:18:23 PM
My CRF Petcock should be here soon, FINALLY.
The stock one has left me stranded countless times. No more. :nono:
keep us posted on how it turns out.I may need to do that swap
Ill put some pictures up. If i get the stuff tomorrow or early thursday, I can do it all then. But I will probably end up doing it all sunday.
Quote from: slowinthestraights on July 31, 2007, 07:56:40 PM
Ill put some pictures up. If i get the stuff tomorrow or early thursday, I can do it all then. But I will probably end up doing it all sunday.
Kool! Thanks! :thumb:
You can also convert your stock petcock to non-vacuum for almost nothing.
That is true. The stock petcock can very easily be converted into the manual valve.
Here is the thread that talks about that with some of pictures I posted of what needs to be done.
Once converted, the notorious fuel starvation problem goes away for good, provided the rest of the fuel pathway is clean.
http://gstwins.com/gsboard/index.php?topic=19363.0
Jenya
Meh. To me, purchasing the Honda one for $24 beats,
A) buying JB weld
B) Messing around with the thing for 30+ minutes
C) having an overcomplicated, oversized, modified petcock
then there is always the option of using a pingle or is it pingel? :dunno_white:
Quote from: yamahonkawazuki on August 01, 2007, 12:53:54 AM
then there is always the option of using a pingle or is it pingel? :dunno_white:
Pingel, and it is something like $75+.
Quote from: dgyver on July 22, 2007, 06:35:47 AM
The vacuum is needed to prevent someone forgeting to turn off the fuel, which if they have bad float valves, the carbs will flood the motor.
The problem with the stock petcock is the check valve in the vacuum port. It will turn to goo from gas fumes and will partially or completely block the the vacuum, which is required to operate the diaphram to allow fuel to flow.
hmmm...I'm gonna check this out. This may be my problem.
Quote from: Jenya on July 31, 2007, 10:24:43 PM
That is true. The stock petcock can very easily be converted into the manual valve.
Here is the thread that talks about that with some of pictures I posted of what needs to be done.
Once converted, the notorious fuel starvation problem goes away for good, provided the rest of the fuel pathway is clean.
http://gstwins.com/gsboard/index.php?topic=19363.0
Jenya
This is prolly the only thread I haven't posted yours and kerry's petcock mod.I have thought about doing it but running on a my petcock on pri is fine.The previous owner driled out the inside of the pri nipple.
I'd always thought about going to a manual petcock, but for three things:
1. I've never had a problem, and
2. I don't remember things, and
3. If a float valve sticks and fills your engine with gas, your engine could be FREAKIN DESTROYED.
The odds of #3 are slim, but if you hydro lock a cylinder and grab some starter, you can break a piston rod real quick. Or, if the gas gets into the crankcase other fun lack of lubrication problems could develop.
Since I'm not at all good at remembering things, I expect to leave a manual petcock turned on quite a bit.
Good advice about busting it apart and checking for problems. Maybe this winter, since my '01 is 6 years old now.
Oh I was thinking about another solution the other day.
My FZR has downdraft carbs which are by necessity above the fuel tank. As a result, it uses a fuel pump that pressurizes the fuel lines to some minimal pressure (like 3psi or something). When the float valves close, the pressure goes up and the pump automatically shuts off. The pressure switch is internal to the pump itself, so there's only two wires going in.
The pump runs any time the ignition computer thinks the engine is running, or supposedly for 3 seconds after the key is turned on.
There's no reason (that I can think of) that you couldn't do something like this on any bike, just drive the pump off a on-at-the-right-time circuit. (Ignition key and or engine killswitch or something.)
So then your overflow safety would be electrically driven instead of vacuum driven. If the fuel pump fails, you need only to bypass the fuel pump and gravity feed it to get home. You could have a valve for this, or just do a field repair type of thing.
You could eBay a fuel pump from pretty much any carbed bike and try it. Or maybe I will and post about it, if I find some weekend that my wife won't be mad at me for spending it in the garage.
Edit: I just realized that this would only work if fuel doesn't pass through a deactivated fuel pump. :)
How about an electric solenoid? Not sure if they are available for fuel service though.
Quote from: dgyver on August 01, 2007, 03:38:32 PM
How about an electric solenoid? Not sure if they are available for fuel service though.
I've been thinking the same thing, so you only get fuel flow when you turn the ignition on.
This was all I was able to find in 2 minutes of searching. :)
http://www.snydersantiqueauto.com/ModelAParts/GasTank/4008
The other thought I had is that when you have the petcock in the off position that it lit up a red led on your dash, when in the pri position it lit up a green led. Would something like this be possible, that way you could tell just by looking at the dash if your fuel was good to go. :dunno_white: :dunno_white:
Quote from: bubba zanetti on August 01, 2007, 05:14:18 PM
The other thought I had is that when you have the petcock in the off position that it lit up a red led on your dash, when in the pri position it lit up a green led. Would something like this be possible, that way you could tell just by looking at the dash if your fuel was good to go. :dunno_white: :dunno_white:
Sure, epoxy a magnet to the end of the petcock handle as well as two reed switches in strategic locations.
-b.
Looking at the options, I think buying a brand new OEM vacuum petcock assembly for $60 every ten years sounds fine. :)
Come to think of it, no one seems to have complained about fuel starvation on a 01+ that I recall. That could just be because they are newer and not all junked up yet, or that they're better. (I'm certain they are different.) The mounting looks slightly different, but it should be no problem putting a 01 petcock on an earlier bike.
Quote from: Chuck on August 01, 2007, 06:14:22 PM
Looking at the options, I think buying a brand new OEM vacuum petcock assembly for $60 every ten years sounds fine. :)
Come to think of it, no one seems to have complained about fuel starvation on a 01+ that I recall. That could just be because they are newer and not all junked up yet, or that they're better. (I'm certain they are different.) The mounting looks slightly different, but it should be no problem putting a 01 petcock on an earlier bike.
This doesn't change the fact that the petcock design is stupid and quite dangerous IMHO. If a hose between the tank and fuel control valve slips off, you can't just turn the petcock off to stop the leak. And are you really going to fiddle with removing the tank to turn off the screw type chicken while gas is schpritzing all over the place?!?! I know there isn't room for a petcock directly on the tank, but Suzuki could have put an electric valve there instead, linked to oil pressure except whilst priming. No oil pressure, the fuel flow should be cut off to avoid a flood in case of an accident with the motor stopping.
-b.
Sadly that's nothing you can fix without buying another bike. I think the odds are slim of disconnecting a fuel line in most accident scenarios that leave the fuel tank attached to the frame. Certainly not as high as the odds of me forgetting to turn the valve off prime when I get to the office 20 minutes late.
Quote from: Chuck on August 01, 2007, 06:46:28 PM
Sadly that's nothing you can fix without buying another bike.
Two electrovalves connected to the tank nipples by way of short hoses, a 3-position switch, and a y-junction? Should be easy...
-b.
ANOTHER OPTION
I own a Concours, so by association, am a cheap bastard. :icon_rolleyes:
Concours has the dreaded vacuum petcock too.
I went to True Value lawnmower section, bought a stupid little plastic 90 degree in-line shut-off valve for lawnmowers, and installed it after the petcock.
Only a couple of bucks.
Cheap enough to replace every year.
Concours tank is high, and holds 7.5 gallons- that's a lot of gasoline to leak past a faulty float valve, many people have experienced the thrill of cranking an engine, when one or more cylinders are full of liquid gasoline. :mad: :mad: :mad: :mad: :mad: :mad: :mad: :mad:
(Connecting rods aren't supposed to be banana-shaped, right? :dunno_white:
Quote from: MikeNW on August 01, 2007, 06:53:33 PM
I went to True Value lawnmower section, bought a stupid little plastic 90 degree in-line shut-off valve for lawnmowers, and installed it after the petcock.
And just plug the main nipple on the tank, only using reserve and keeping good track of the odometer?
-b.
Here's the Honda gas tap that we have been talking about - mine came in tonight at the dealers after I ordered it Wednesday evening.
(http://i16.photobucket.com/albums/b18/BTGirl/BikePix/2007_0803GS5000001.jpg)
and here it is next to the original Suzuki one.
(http://i16.photobucket.com/albums/b18/BTGirl/BikePix/2007_0803GS5000002.jpg)
There is a locating ridge on the rear of the Honda one that will need to be ground down for a good fit, and I found I will need some more fuel line as the stock length is now too short. The main feed line to the carbs exits at the rear of the Honda tap. The Honda one has a nice big handle to hold onto, bigger than the Suzuki one.
Quote from: Chuck on August 01, 2007, 06:14:22 PM
Come to think of it, no one seems to have complained about fuel starvation on a 01+ that I recall. That could just be because they are newer and not all junked up yet, or that they're better. (I'm certain they are different.) The mounting looks slightly different, but it should be no problem putting a 01 petcock on an earlier bike.
I had fuel starvation all the time on my '92, and it hasn't happened once on my '01, even during long high-speed trips loaded with a passenger and luggage. Whether that's because of fewer miles or because of a different petcock is anyone's guess. However, the '01 petcock is definitely different (at least on the outside).
I found a simple way of modifying the stock 2004 - 2007 petcock so it can be converted to a manual operated system.
http://gstwins.com/gsboard/index.php?topic=37366.0
Regardless of whether you buy a new frame petcock with out a vacuum line or modify the old one to NOT use a vacuum line, what do you use to "plug" the port on the carb?
Thanks
Sam
Quote from: KokomoSam on November 16, 2007, 04:13:48 PM
Regardless of whether you buy a new frame petcock with out a vacuum line or modify the old one to NOT use a vacuum line, what do you use to "plug" the port on the carb?
Thanks
Sam
A vacuum cap. Another option is to cut the line and plug it with a screw.
Doesn't the Pingel petcock have a valve handle the faces straight down out of the tank and can be reached from below, with the tank in place? I was under the impression that was one of the big benefits of the Pingel--completely rip-out both stock petcocks (tank and remote vacuum operated) and have one manual petcock at the tank, with one fuel line running to the carbs.
Now, I'm apparently flirting with disaster here has I've ripped out the second petcock, directly plumbed the fuel into my carbs from the prime outlet of the tank petcock, and just added a valved quick couple inline. With how much I've had to take that tank on and off, the valved quick couple is wonderful. (Too bad I broke down and bought after most of that work.) I could add an inline valve, or if I wasn't so cheap, I'd spring for a Pingel. (That and having to completely empty the tank again, file-out the hole to accept the Pingel petcock, etc.)
So, how long till I blow-up my engine by filling it with gasoline? :oops:
-B.
(P.S. if I know I'm going to be sitting the bike for a while, like when it's been out of service, I do disconnect the quick coupler.)
Quote from: Chuck on August 01, 2007, 06:46:28 PM
Sadly that's nothing you can fix without buying another bike. I think the odds are slim of disconnecting a fuel line in most accident scenarios that leave the fuel tank attached to the frame. Certainly not as high as the odds of me forgetting to turn the valve off prime when I get to the office 20 minutes late.
Quote from: dgyver on November 16, 2007, 07:53:39 PM
A vacuum cap. Another option is to cut the line and plug it with a screw.
Dgyver,
Thanks for the answer. I am a newbie enough at working on my bike that I have to ask, where do I get a vacuum cap and what size will I need?
Thanks
Sam
Auto parts stores carry them. Not sure the exact size, but 3/32-1/8" should be fine. I believe they they can be purchased in a variety pack. In a crunch you can use plastic caps (typically used as thread protectors) found at hardware stores but they will become hard and may eventually crack.
Quote from: simoniz on August 03, 2007, 05:50:23 PM
Here's the Honda gas tap that we have been talking about - mine came in tonight at the dealers after I ordered it Wednesday evening.
(http://i16.photobucket.com/albums/b18/BTGirl/BikePix/2007_0803GS5000001.jpg)
and here it is next to the original Suzuki one.
(http://i16.photobucket.com/albums/b18/BTGirl/BikePix/2007_0803GS5000002.jpg)
There is a locating ridge on the rear of the Honda one that will need to be ground down for a good fit, and I found I will need some more fuel line as the stock length is now too short. The main feed line to the carbs exits at the rear of the Honda tap. The Honda one has a nice big handle to hold onto, bigger than the Suzuki one.
Is the position of the CRF petcock the same position that you install it in?