Announcement

Collapse
No announcement yet.

NEWBIE: How does the petcock work?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    NEWBIE: How does the petcock work?

    Hi
    I think my petcock is broken or maybe i am not getting how it works. I have taken the gas tank off and twisted the screwhole with a screw driver in every direction and no gas flows out. I pulled it apart and checked everything out and it looks fine. If I suck on the vacum hole, the little cylinder to bring the gas in moves down. How does the primer switch make it do this to put gas in the carbs? I dont see how.

    Another question is.. with no gas in the system, will the vacum tube suck when i try to start it?

    Alex

    #2
    Here ya go alex http://www.dansmc.com/gastank.htm not too detailed but simple to understand. If you want more detailed info just reply and I'll see what I can find.

    The primer switch should just be like a drain I think. It dosent even need vacuum it should just pour right out. I think the vacuum is mainly so you dont get too much gas in your carbs and overflow. The vacuum will just give what ever the carb needs.

    Is this a new bike for you? If not was it running before? Did you just take it out of storage? Leave the old gas in it? If so It may have turned to snot inside there and clogged it up. I would remove the pedcock from the tank and blow where the fuel hose should go and see if anything comes shooting out of the top. You may want to put some goggles on if you do that, gas in the eyeballs dosent sound like much fun.

    Remove the gas cap and look inside the gas tank, is it rusty? The petcock may be clogged with bits of rust in it. Lemme know what happens.

    PS I'm an idiot so if anyone else has another idea, do that first :P

    Comment


      #3
      Re: NEWBIE: How does the petcock work?

      Originally posted by alex1ld
      Hi
      I think my petcock is broken or maybe i am not getting how it works. I have taken the gas tank off and twisted the screwhole with a screw driver in every direction and no gas flows out. I pulled it apart and checked everything out and it looks fine. If I suck on the vacum hole, the little cylinder to bring the gas in moves down. How does the primer switch make it do this to put gas in the carbs? I dont see how.

      Another question is.. with no gas in the system, will the vacum tube suck when i try to start it?

      Alex
      If you have the petcock I think you have , when you turn the screw slot to pri, you close off a bleed hole, so then you still need a brief bit of vacum,what the pri does with this petcock is it keeps the petcock from returning to off after a breif bit of vacum is removed , you then need to turn the slot off of pri to turn the gas off.But bottom line is you still need vacum to get the ball rolling (or gas flowing)so in pri when you try to start a dry carb, motoring the engine for a sec will provide the vacume needed, to get the gas going(open the petcock) , all you have to do is wait a minute for the carbs to fill, then return the slot to the horizintal position/for normal engine on gas: engine off /no gas

      Comment


        #4
        How does your screen look?

        How does the sreen look. those sreens are super fine, and easy to clog. Clean it up with some warm soapy water and a soft tooth brush. If your petcock is fine it may make a world of difference. It's the only thing I can think off that would keep fuel from flowing while set to prime. I'd stop fiddling with the petcock. If it's not broken now it will be after you take it appart a few more times. Then the fuel will end up in your crank case, and all over the garage floor.

        Comment


          #5
          I took out the spring out below the diaphram so it would always be on. I know the gas will flow, i just think something is wrong with the primer switch.

          Comment


            #6
            Originally posted by alex1ld
            I took out the spring out below the diaphram so it would always be on. I know the gas will flow, i just think something is wrong with the primer switch.
            I performed the same mod as you describe on our last HC ride, but you stand a good chance of filling your crankcase full of fuel if your needle and seat valves do not shut off the fuel flow completly. I would suggest you clamp off the fuel line between your petcock and carbs when the engine is not running. My .02 worth.

            Comment


              #7
              that has already happened, i just did it to see if fuel would flow.

              Comment

              Working...
              X