using choke to kill engine?

Discussion in 'Motorized Bicycle General Discussion' started by skyyseeker, Oct 7, 2011.

  1. skyyseeker

    skyyseeker New Member

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    My kill switch isn't working and i was wondering if it's bad to use the choke to kill the engine instead?
     
  2. The_Aleman

    The_Aleman New Member

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    Welcome to the forum!

    I always used the choke to kill on a 2-stroke myself. Many here have. It's only bad if your choke won't stop the engine! :D

    Kill switches are convenient, as long as they work correctly.
     
  3. wayne z

    wayne z New Member

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    It's always a good idea to kill a 2 stroke engine with the choke when you don't expect to run it for a while. Leaves extra oil in the engine to help with corrosion control.
     
  4. Al.Fisherman

    Al.Fisherman New Member

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    Actually I feel that "kill" stopping the engine from running by the choke by itself isn't all that good. I myself will cut off the fuel supply at the tank about 500' from where I'm going to stop, if for a prolong time. Then use the kill/choke. I use the kill switch as all my builds, I haven't had any problems with them. I cut off the fuel to relieve any pressure on the needle and seat.
     
  5. BarelyAWake

    BarelyAWake New Member

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    Using the fuel petcock to stop fuel flow before shutting down the engine can cause a lean condition and reduce the amount of available lubrication, which can contribute to premature wear and difficulty starting.

    Personally, I'd just shut off the fuel after engine shutdown, choke or otherwise.
     
  6. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    For two stroke HT's, I gently let out the clutch lever to stall the engine.
    If for some reason that won't work (such as a broken clutch cable), Then I recommend using the choke! ;)
     
  7. 2door

    2door Moderator
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    No one has addressed the safety issue involved with a working kill switch.
    They are not just a convenience. They are a method of shutting down the engine in the event of the need for a panic stop situation. There have been a number of reports of a sticking throttle/runaway engine posted here on this forum. Granted, that's usually due to improper installation of the throttle cable or a carburetor malfunction, nevertheless.

    Imagine youself doing 25, 30mph or more and coming to a busy intersection, your throttle sticks open and you fumbling down between your legs looking for the choke lever. As far as using the clutch to shut off the engine, That won't work at 30mph.

    If you don't have a working kill switch that is handy to reach in an emergency, you could be setting yourself up for an accident.
    Tom
     
  8. Goat Herder

    Goat Herder Gutter Rider

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    I concur with 2Door this is a very nice safety feature to have.:)
     
  9. Al.Fisherman

    Al.Fisherman New Member

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    Please do tell.... how can closing the fuel valve be a detriment to the engine. If you notice, the engine is still running, draining the bowl of some fuel (releasing pressure on needle and seat), then I shut the engine down using the kill switch. Never said it ran out of fuel.

    Look at the thousands of dollars spent on outboard engines, shutdown, pull the fuel hose and burn up what fuel is left in the carburetor. Although it's better to remove the drain plug in the carburetors to drain fuel after the engine is stopped..
     
    #9 Al.Fisherman, Oct 7, 2011
    Last edited: Oct 7, 2011
  10. BarelyAWake

    BarelyAWake New Member

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    I think we're "splitting hairs" here, it's simply an unnecessary procedure without any perceivable benefit yet with a slight chance of the minor detrimental effects mentioned above. I'm not sure why the minuscule "pressure on the needle and seat" is something to be concerned about as it's a normal function of the carburetor. The OP was asking about routine engine shutdown, save for long term/seasonal storage draining the fuel from the carburetor is simply unneeded, should it leak, it needs to be repaired and/or the fuel supply shut off while parked.

    While not critical for our application, enriching the fuel/air mix via choke/enrichment circuit to initiate engine shutdown is SOP for ultralights and other small prop aircraft for the reasons previously stated.

    BTW, the correct procedure for the winterization/long term storage of an outboard when disabling the fuel supply is to introduce a "fogging oil" while the engine is still running to prevent corrosion as well as lubricate a two stroke during this lean condition.
     
    #10 BarelyAWake, Oct 8, 2011
    Last edited: Oct 8, 2011
  11. skyyseeker

    skyyseeker New Member

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    Wow. That's a lot to take in. Um, i guess i'm getting that's it ok to use choke to shut down the engine as long as i turn the fuel off too... it won't hurt the engine if i do it. I don't know why my kill switch stopped working, just kinda happened one day. I checked all the wires and they are still connected. So, i dunno. Anyway, thanks guys for answering my question...the outboard engine stuff was interesting too. ;)
     
  12. Acraze

    Acraze Member

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    Ive started to use the choke to turn mine off as well, I'm guessing the stock switch is crap and thy why when I hit the kill switch it just does mini not loud backfire sounds, takes about 8 seconds to die. I've also attached a long zip tie to the choke arm on the carb so it is fairly easy to just pit hand down and pull up.
     
  13. Goat Herder

    Goat Herder Gutter Rider

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    IMHO I say there is way more so called pressure on the said needle valve when the bike is running. These engines vibrate. That is a night and day difference from simply sitting still.

    I get what the guy said he did not run it empty just split the difference. That sounds peachy. Still taking a hand off the bars. Alls I am saying is to be care full guy's and alert! Its not do as I say lol I remove my hands sometimes for a second on extra long rides when there are a little cramped just to flex them and stretch them a little.

    I stalled my china's to turn it off before from an Idle that is harmless enough.

    The easy to reach zip tie sounds nifty..
    Your still have a hand missing from the handle bars. This sounds terrible at 30 miles an hour. Or any speed I think.
    http://stores.ebay.com/OZG-POWERSPORTS/Switches-/_i.html?_fsub=2032298015
    Here is a link
     
  14. donb4103

    donb4103 Member

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    Some of the kits that are around don`t even have kill switches in them. I think some of the factories are trying to wean us off of some of the frills and keeps their profit up that way. It really doesn`t matter how you kill your engine once you are ready to stop. If your fuel mixture is right then you are not going to be drying anything out or leaving anything too rich either way you kill it. some people have just developed their own way of doing things and are not usually easily made to change the way they do things. Just decide how you want to kill it and then be consistant in doing it that way. These little 2 cycles are a lot like diesels and can be rather mean to changes.
     
  15. rommel

    rommel New Member

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    I prefer to use the choke for routine shutdown, it's SOP with a lot of light aircraft pilots. I also like having a kill switch available for times when I want to shut down my motor while rolling, like when I see a cop up ahead :)
     
  16. nightcruiser

    nightcruiser New Member

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    I run the CNS carb with the enrichment jet type of "choke" that has the old school shifter lever that mounts on the handle bars. I didn't care for that lever, since I never use the front dérailleur any more I ran my "choke" cable to front dérailleur lever (thumb shifter lever on old school mountain bike). I love this setup cause I can hold the enrichment jet open easily with my thumb, if I don't latch the lever it snaps back closed when I let go. I find I only need the enrichment jet for very short periods so this works great.
    A side benefit is I can now use this shift lever to kill the motor via the choke without removing my hands from the handle bars...
     

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