fuel stops flowing

[MexicanMafia]

so now i got the bike running again i have a problem with the fuel flow. it'll do good for about 20 mins of riding or so, and then the fuel will stop flowing thru the lines. i can see it stop thru my inilne filter. so i took the tank off and cleaned it out. check the petcock, it's good and flows good. so now my only guess is a stuck float but i just went thru the carbs and check the float valve and the housing and it all looked good with lil to no ridges on the rubber points. anything else that could be causing it to stop flowing.


i can blow thru the lines and then hook it back up and it'll start goin again. would this indicate a stuck float?? thanks.

[Johnj]

Sounds like your fuel tank vent is plugged. Try riding until the bike dies. Open the tank. Do you hear a hissing noise as the tank opened? Close the tank and try to start the bike.

[storysunfolding]

Sounds like your fuel tank vent is plugged. Try riding until the bike dies. Open the tank. Do you hear a hissing noise as the tank opened? Close the tank and try to start the bike.

+1

[MexicanMafia]

yea i do sometimes. but after i open it, it still won't flow. and if i don't open it and just pull the line off fuel will flow out of the petcock. also where is the tank vent for this, the other tube out of the petcock?? thanks.

[flynrider]

You'll have to check a manual for the location of the tank vent. Many have a vent in the cap, but not all of them do. A clogged vent will prevent fuel from flowing out of the tank after it's been running normally for 10-20 min.

The fact that you see the fuel flow stopping in the line/filter, pretty much rules out the carb floats, doesn't it? The problem has to be in the tank, petcock or fuel line.

You mentioned that you have another tube going into the petcock. That would indicate that you have a vacuum operated petcock. If the vacuum line is leaking, it could restrict fuel flow. Also if the vacuum diaphram inside the petcock is damaged, same deal. Just about all vacuum petcocks have a position labeled "prime". You can bypass the vacuum function by using this setting. Next time the fuel stops flowing, put the petcock in the "prime" position. If you see the fuel start to flow, then your problem is likely in the vacuum line or the diaphram.

[MexicanMafia]

i don't think it's the petcock casue when i unhook the line fuel with come out with tring to start the bike and stops when quit cranking it over. i can blow into the line goin to the carbs and hook it all back up it'll go for about 5 mins now and then stop flowing again. this is with the tank open too.



also there is no prime position, just off, on, and res

[Pongo]

Also if the vacuum diaphram inside the petcock is damaged, same deal.

I agree... But firstly remove and clean the vacuum diaphragm. If that doesn't work and it is damaged you will need to replace the whole diaphragm assembly as a unit.

Do you have a service manual?

[MexicanMafia]

yes i have a manual. i check the petcock a while ago and the diaphram and spring look good and new. i think it works too cause when i unplug the line and start it it'll flow fuel and then stop when i stop, jsut when the line is hooked up it'll only flow for a min. you think that there's more pressure in the line or something? thanks.

[Johnj]

Still sounds like your tank isn't venting.

[MexicanMafia]

i don't think it's the petcock casue when i unhook the line fuel with come out with tring to start the bike and stops when quit cranking it over. i can blow into the line goin to the carbs and hook it all back up it'll go for about 5 mins now and then stop flowing again. this is with the tank open too.



also there is no prime position, just off, on, and res