Help! 4 stroke bike not getting fuel.

Discussion in 'General Questions' started by bikejock, Jun 5, 2015.

  1. bikejock

    bikejock Member

    I was trying to start my bike again & it wouldn't start after like a dozen pulls of the pull start. Tyen I noticed fuel wasn't flowing through the fuel line. I just got a replacement valve &I I know that works because after I pulled the fuel line from the valve it spilled fuel when it was off & stopped spilling when I turned it off. What is causing this? Is it my fuel filter or something else? I got one of those fuel filters for 75ยข from Phantombikes if that helps at all.

    The fuel line that goes from the bottom of the fuel filter to the carb is filled with fuel but the line going from the top of the fuel filter to my valve isn't getting any fuel flow. Anyone know what's going on? First time it's ever happened.
     
    Last edited by a moderator: Dec 18, 2015

  2. Timbone

    Timbone Active Member

    Remove the fuel filter.
     
  3. bikejock

    bikejock Member

    Tried that. Didn't solve the problem. The problem seems to be with my carburetor because when I turn the screw that drains the fuel it flows through from the tank just fine but when I tighten the fuel drain screw stops receiving fuel from valve to carb.
     
  4. crassius

    crassius Well-Known Member

    what you describe sounds like the carb bowl is full. but you're not drawing anything into engine - a clogged jet would be first guess here

    if you hold your hand over mouth of carb when you pull it, does your hand get wet? does carb look wet inside?
     
    Timbone likes this.
  5. bikejock

    bikejock Member

    I unbolted the fuel bowl & cleaned it out. After that I hooked up the carb to the engine & plugged in my fuel line & turned on the fuel valve. After that it got some gas but the problem I was having before came back so now my fuel is being blocked at the carb.

    There's a chance that the fuel I used may have been contaminated & some of the contaminants may have got passed the filter & clogged the jet because I think the jerry can I used to fill up the bike was proabably dirty inside.

    Any thoughts on a good way to clean a jet/jets on an HS 142F carb?
     
  6. darwin

    darwin Well-Known Member

    Do you have an air compressor? If your like me and do not then the best way to clean the carb is with a can of compressed air you use to dust off computers with. Use it to blow through the jets with the nozzle tube that comes with a spray can. Using a wire first to poke through all the holes will help too. Your idle jet is a black plastic piece located below your black plastic idle adjuster screw on top of the carb. Be careful pulling it out it's delicate and plastic. Blow it out best you can. The idle jet hole is so small the only wire I could find in my box to poke through it was a fine brass wire off a brass wire brush. There's 1 or 2 o-rings on that jet, they must be intact when you reinstall the jet. They must also be seated correctly into the grooves that hold them. When reinstalling the jet a lil lube like wd40 helps to ease it back in.......instead of compressed air a can of wd40 with a spray nozzle works too, do it outside cuzz the fumes will overwhelm you inside.
     
  7. bikejock

    bikejock Member

    After draining the fuel bowl I noticed allot of bubbles in the fuel bowl drain tube. Does this confirm a clogged jet?
     
  8. darwin

    darwin Well-Known Member

    If you mean the overflow tube for the bowl then no it does not. Clogged jets usually have a symptom of eratic idling, eratic revs when throttling up, in other words runs like crap. Another thing that helps is to soak carb completely under a cleaning solution when disassembled, then proceed to blow through the jets and use a wire if needed. Gas works if you submerge it. Carb cleaner works, just spray the jets and soak the carb and let it sit for an hour or so then clean it up. Lots of ways to do it.
     
  9. bikejock

    bikejock Member

    I broke the jet trying to remove it so I'm getting a new carb. I'll keep the one with the broken jet for spare parts. I should get the new carb by tomorrow. I wish these things were made with better quality parts but the price of the kit would skyrocket. There's a few things I plan on upgrading like a few nuts & bolts & probably the rear drive sprocket.
     
  10. butre

    butre Well-Known Member

    I have no idea how you managed to break a jet
     
  11. bikejock

    bikejock Member

    Alright so I got the new carb & installed it. Turns out I'm STILL not getting fuel! Looks like the float in the carbs fuel bowl won't go back down. Is this a desighn flaw with carbs? I'm using regular unleted gas fresh from the pump so gas shouldn't be the problem.
     
  12. crassius

    crassius Well-Known Member

    I'd guess some simple error here rather than a design flaw.
     
  13. bikejock

    bikejock Member

    Just out of curiosity, has anyone ever adapted a 2 stroke carb to a 4 stroke?

    Back when I had my 2 stroke bike I never had any problems with the carb on that bike. But on my 4 stroke the only problem I'm struggling with the most is the carb on my HS 142F.

    Also a fuel injection system would be awesome for these 4 stroke motors & proabably give some extra performance.

    It's a modern 4 stroke so you'd think fuel injection would be standard on 4 strokes of any size these days. Carb fuel systems seems pretty primitive.
     
  14. Slogger

    Slogger Member

    I'd say go back to square one here. Put your palm over the carb throat, seal it off, open the throttle and pull the rope.
    Your hand should get sucked on by the vacuum.
    If it doesn't, you either have a stuck closed intake valve or broken off cam lobe in there or something.
    If it does, you have a clogged inlet fitting, float needle seat or main jet if it isn't getting any gas at all.
    So, does it suck air?
     
  15. Slogger

    Slogger Member

    I just saw your last post, about fuel injection.
    EFI requires high fuel pressure, a lot of electrical power and precise senders for the crank position that tells the computer when to inject fuel and how much. Throttle position sensor, mass flow sensor, on and on. About 10 amps of 12 volt power required.
    It's just not feasible on a $200, wee little engine.

    I have read of others using NT carbs on HF engines. They say they worked fine.
    Hope this helps some.
     
  16. The_Aleman

    The_Aleman Active Member

    Are you sure your gas tank cap is venting properly? Try starting/running the engine without the gas cap.

    Sometimes those vented caps don't work very well.
     
  17. KCvale

    KCvale Motorized Bicycle Vendor

    Yes.

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    The HS intake holes are the same as a 2-stroke intake so you can use a 2-stroke intake.
    An offset worked best, we just did some creative cutting.

    Get a catch can for the breather hose, it hampers performance if put in the air cleaner like that last one.
     
  18. bikejock

    bikejock Member

    Ok after installing the new carb I still was getting fuel line blockage for what ever reason from half way from my fuel line to the tank. But I was able to use the fuel that was in the line & fuel bowl to get it to start again. But the problem is it won't start unless I have the throttle open which could be bad for the engine always having to start it that way.

    People say that having to start an engine with the throttle open is often a sign of flooding but I don't think that's the case here. If it were flooding, I would see gas leaking out of the carbs clear exaust tube.

    The problem that might be causing this could be the float bowl keeps filling to high causing the float to be in the up position all the time, a clogged jet (don't see that being the case since it's a brand new carb), float level set incorectily (these carbs have no way to adjust the float level which IS a huge design flaw if that's the problem), using ethonol fuel (doubt that's the problem because I'm using regular unleted gas straght from the pumps so it should be ethonol free fuel)
     
  19. crassius

    crassius Well-Known Member

    I'm not sure that you are understanding the float - it is supposed to go as high as it needs to shut off the fuel, then drop a bit as fuel level goes down from use to let in more fuel. If you're not using fuel, it will not go down.
     
  20. bikejock

    bikejock Member

    I understand what a float is for problem is I don't think it's working right. Problem is I have no way to figure out why.

    The problem is the float won't go down even when I'm trying to use fuel. My fuel valve is in the on position & I got about $1 worth of gas in the tank for testing.

    The fuel flows for about a few seconds then an air pocket developes between the middle of the fuel line where my filter is & the gas tank. I know it's not the fuel filter causing the problem because I unplugged my fuel line from my carburetor to drain the gas & it flowed out through the line just fine even with the filter installed. That's why it has me thinking my float is up without ever coming back down after the fuel bowl fills up with gas.
     
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