Bad Petcock
The petcock/fuelcock on B4s can go bad and create all sorts of problems (I know from first-hand experience). One theory I've heard is that it is caused by the oxygenated fuel used in the US drying out the rubber internals of the things. Here is an example from the old board with some good info...
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BlueSeaSailor
(7/26/02 12:55 pm)
HELP..bike not startin...please come in and take a look
Hello,
I had my carb cleaned and overhauled by a mechanic from a suzuki dealer. However, the mechanic cannot ride it after he finished overhauling the carb because my gas tank was leaking.
After I patched up the gas tank and put it back on the bike. I cannot get the bike to start at all and it seems that the carb is not getting gas for the gas tank to start. I put gas in the carb itself using a tube then the bike started for about 3-5 minutes. And then it stopped. After it had stopped, I could get it started again. I don't know what is causing this. Can anyone tell me what might be wrong with my fuel system? or anything... I did pulled the fuelcock off and cleaned it also, and I am sure I put it back right. Could anything be wrong with my fuelcock? or anything else. I really need some comment on this...so please give me a hand..^_^ Thanks
have fun and ride safe
Vince
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DjSuperfly
(7/26/02 1:31 pm)
try these...?
Check for kinks in the fuel line when the tank is down...
did you put a filter in the fuel line...check when you're trying to start the bike...if bubbles are forming in the filter...then there is suching form the carbs and rule out everything below the filter...check the pressure equilization tube...there should be three tubes, two the the petcock and one to the tank, are they hooked up to the right ones...do you have a full tank of gas...take the tank off, and turn the petcock on, you should get a nice drip/flow of gas coming out...these are the only things I could think of...hope it helps...
Bao
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BlueSeaSailor
(7/26/02 5:21 pm)
Re: try these...
Bao,
thanks for the input. I took the gas tank off and turn the fuelcock to the on position and gas is not dripping out. Is it suppose to drip/flow? How can you check if my fuelcock is brocken?
Vince
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Red01SuziB12S
(7/26/02 7:19 pm)
Fuel petcock
Doesn't the B4 use a vacuum operated petcock??? If so, you won't get any fuel out of the tank in "ON" or "RES" unless the diaphragm has vacuum applied. If the petcock is in the "PRI" (prime) position, it should flow fuel without vacuum though.
Paul W
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DjSuperfly
(7/26/02 9:43 pm)
oops...
yes, thats right...our petcock is vacuum operated...
Thanks Paul...
there is no prime position...there's only fuel and reserve...both of which require vacuum from the second smaller hose...check to see if that hose is producing any vacuum...
Bao
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Red01SuziB12S
(7/26/02 10:05 pm)
No "PRI"???
No prime position? How do you get fuel in the carbs after they've been drained? Will it provide enough vacuum just turning it over with the starter?
Paul W
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BlueSeaSailor
(7/26/02 10:49 pm)
How much vacuum is enough?
Bao,
How much vacuum is enough? I did check if it is creating a negative pressure. When I put my finger on the vacuum tube, I felt sucktion. But, I don't know if that sucktion is enough... what do you think? If it still doesn't work tomorrow, I will order a new petcock from a suzuki dealer. The parts guy told me it's going to be $75!!!!!!!!!!! Why is it sooooo expenSIVE??? By the way, could the valve in the petcock be broken? I sucked on the place where you connect the vacuum tube and I kept hearing that click sound everytime I applied sucktion on it. However, I was not getting and air by sucking on the place where you connect the vacuum tube. It is like sucking on a frozen milkshake. Again, thank you guys for your inputs
have fun and ride safe
Vince
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Red01SuziB12S
(7/27/02 12:52 am)
Re: How much vacuum is enough?
It should be rebuildable with a new diaphragm and new o-ring(s) without shelling out for a whole new petcock. If it's not, I'd try bike dismantlers, I'd think the petcock was used on more than just the B4.
Paul W
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Oyabun
(7/27/02 6:14 am)
petcock and fuel flow
Hi guyz.
Quick advise from somebody who been there, done that.
The vaccum what the manifold creates enough to keep the bike running, but you'll drown the battery before it will fill the carbs. Use some alternative vacuum source (eg. your mout, do not be afraid you won't get fuel in your mouth) to do it. Actually you can hear when fuel fills the carb. You can also check if the floating bowls are filled with the tiny screws on the bottom of them.
Don't ask me how I know... :-)
Cheers
Oya
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BlueSeaSailor
(7/27/02 10:43 am)
petcock and fuel flow
Oya,
I did suck on the vacuum port and the gas didn't come out. I am thinking my whole petcock has gone bad.
Vince
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Lizardking
(7/28/02 10:29 pm)
Petcock
well, its not unheard of, and actually quite common for the fuel petcocks to go bad. You can look into a Pingel if looking to upgrade.
If you have had bad gas in your tank before (like if the overflow passthru tube gets clogged and overflow water enters the tank, then you might want to empty the tank, invert it and remove the petcock and clean the screens by blowing air backwards through the valve.
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Oyabun
(7/30/02 3:18 pm)
Petcock
Hi Vince
I might not have been very understandable (sorry, some fever and flu makes me a bit dizzy).
If you suck the vacuum line, you should NOT get any fuel into your mouth. If you'd to then it would mean that the petcock is seriously damaged and should rebuilt.
Fuel should be flowing in the fuel tube, connecting to the middle of the carb banks.
You can alternatively try the whole setup off the bike.
Remove the fuel tank, leaving the vacuum and fuel lines on the carbs/ inlet manifold.
Jack up the tank by the two ends with anything you can get, books, some stock of wood, soup plates whatever.
Put something beneath to catch the fuel hopefully leaves from the tank at the right place (best option is fuel outlet :-)
Alternatively get a comfortable length hose, which diameter equals with the vacuum line or use the orig vacuum line. Usually I leave the original in place since it is quite difficult to put it in place when the carbs are on the bike, but it can be different with the non VC model. Any hose will do, no petrol is involved here, I usually use car windscreen washer hoses or hoses used in aquariums. (hint: do not be afraid to buy couple of meters, it will come handy bleeding the brakes, hanging things temporarily or to fabricate an ad hoc water pipe)
So then rig up everything and check visually if your petcock works, without messing up everything with valuable but very inflammable petrol.
Oya
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BlueSeaSailor
(8/1/02 10:54 pm)
Problem solved
Hey guys,
Thank you for your inputs. I got my problem fixed, and the bike is up and running now. I bought a whole fuel @#%$ assenbly and installed it on the fuel tank. Put the tank back and connect the fuel hose and vacuum hose...Then start the bike...and that's when the magic happened....well..not exactly...but after all the trouble it's been through..I'd consider it a magic. THE BIKE STARTED...^_^ Of course I am happy....since I can at least ride it....but I still have problems to deal with on my Bandit 400....my shock is blown out, and second gear is messed up....those are 2 major problems...others are just cosmetic works.... But at least I can try to address on those problems when I have time. Again, I appreciate your support and inputs...
have fun and ride safe,
Vince
Topic: Petcock Issues (Read 12165 times)