No or very little fuel in fuel filter

Discussion in '2-Stroke Engines' started by crackers, Jul 19, 2009.

  1. crackers

    crackers Member

    Don't know whats going on. I took the gas tank off and opened the petcock valve and fuel comes out fine, took the valve off and blew through it with the handle in the open position and it was clear, put it in the off position and couldn't blow throw it, installed it back on the tank and hooked the fuel line with inline filter back on the petcock valve, put the handle in the open position and fuel comes out enough to fill up a spray paint cap lid in a few seconds. When I blocked the end of the hose ( the end that would fit on the carb.) off with my thumb I expected it to fill up the line below the filter and fill the fuel filter. But no fuel was even in the bottom end of the hose. Is this a vacume problem? Funny thing is when its hooked up to the engine you can't see fuel in the filter but it runs with out running out of gas! Every once in a while the filter will have a very small amount of fuel visible in the bottom of it. I've tried removing the gas cap to see if it would fill up then but no change. This just doesn't look right to me and I don't want to brake down on a long ride. Any idea's:helpsmilie::helpsmilie:

  2. give me vtec

    give me vtec Active Member

    mine does that too... part of my fuel line sags below my carb... its because these engines use gravity to get the fuel to the engine. Make sure that your tank and all fuel lines are well above your carb. Can you post pics.
  3. crackers

    crackers Member

    I'm pretty sure thats not whats going on but here's a pic, I wondered if my tank wasn't mounted far enough back on the frame for the fuel to reach the petcock valve when its low on fuel so I filled the tank but no help there.

    Attached Files:

  4. give me vtec

    give me vtec Active Member

    yeah tank and fuel lines look good. Try to take a 2 foot length of fresh fuel line, or a straw or something and take the gas cap off. put the tube in the tank without putting it in the gas and seal your hands around the opening. Blow in the tube or straw with compressed air or your mouth to pressurize the tank and see if that works.
  5. thats why i always use clear line so i can see the gas move threw it.
  6. crackers

    crackers Member

    Well today I tried blowing into the tank and that didn't do anything except leave a bad taste in my mouth, it did sound like it might work. When it didn't I shut off the petcock valve and removed the hose thinking there would be some gas in the hose below the fuel filter, but nothing. I then blew through the hose and again it was clear. I turned the valve on the tank to the run position and had gas flow. I then reinstalled the hose to the petcock valve but not yet to the carb. Checked it again with the petcock valve in the run position and had fuel flow but it was week, switched valve to the reserve position and had a strong flow, put my thumb over the open end of the hose and Bingo the hose and fuel filter filled all the way up. It looks to me like I should be able to run the engine in the reserve position all the time, not sure how that valve works as there's only one exit out of the tank and I couldn't see where the tank is divided any place. I think it's time to find a better quality petcock valve! I'm sure I've read somewhere on here that these valve's have some type of special pipe threds or something. Anyone know where one could be purchased off line? Home Depo Lawn mower shop ect.
  7. give me vtec

    give me vtec Active Member

    I got the better valve and filter from sick bike parts. Much better quality.

    Sorry for the bad taste in your mouth thing... thats why I use a long tube.
  8. srdavo

    srdavo Active Member

    Not to worry...that little trickle of fuel will be plenty to keep your bike running. I've seen lots of them that never fill the lines & filter.

    as the Mountainman says...."Ride that thing"
  9. graucho

    graucho Active Member

    Totally true Dave.

    Hi crackers, My experience with MB's, Mini choppers and road bikes most of them never fill the line all of the time. The float fills up and the needle shuts off the fuel supply to the bowl. When the float calls for fuel, the needle/bowl only allows enough volume of fuel to enter the line until the needle/float fills up and shuts it off again.

    The only time i see the line near full of fuel is if I go out for a good hour ride and the float probably refills the bowl a hundred times. A trickle of gas in the line is normal. Unless the needle gets stuck and your not getting gas into the float bowl at all.

    These float bowls are so tiny it only takes a second to fill the bowl then the needle seats, not allowing enough time to fill the line. If these float bowls were 4 times the size it would allow enough time to consistantly fill the line.
    Last edited: Jul 20, 2009
  10. crackers

    crackers Member

    Thanks guy's that makes me feel a lot more confident about taking longer trips, so far I haven't been venturing to far away from home. Trying to make sure everything is up to par or close to it.