Properly killing the engine

Discussion in '2-Stroke Engines' started by zamanakhan, Nov 15, 2009.

  1. zamanakhan

    zamanakhan New Member

    When iam done riding i turn off the fuel petcock while the motor is on and wait for the rpms to raise just a lil bit before i turn it off. This pretty much gets rid of the gas that should be in the carb, is this a stupid idea? am i wreckin the engine? should i just turn the petcock to off and then just hit the kill switch? or does it even make a diffrence?

  2. 210061741

    210061741 Guest

    Disconnect the white wire and the Kill switch.
    If you want to put a switch on the blue line.
    The kill switch is bad on the magneto.

    I run Bule coil wire to blue cdi wire.
    Black coil wir to Black CDI.

    The white wire is disconnected or could be used for small low powered lights.

    I just put the choke all the way to close and give it full throttle to shut her off.

    Sure it sucks in some fuel oil but i feel it keep things lubed up.
    A little extra oil never hurt.
  3. fetor56

    fetor56 Guest

    When i'm done for the day & heading home i turn the fuel off & when i'm out of gas i coast into my driveway....good how u can judge it coming from any direction.
  4. Turtle Tedd

    Turtle Tedd Member

    Yup ..that's the way I do it..even though I have a kill switch...less gas smell when I put it in the garage....figured out how far away to shut the fuel off..pull in the drive, get off, take two steps back, put my hand in the air and it stops (just for the neighbors who might be watching)
  5. AussieSteve

    AussieSteve Active Member

    There is nothing wrong with using the white wire for a kill switch. That's what it is intended for, not for lights. If you run lights off this wire, you will be drawing energy from your ignition system, like a partial kill switch and will reduce spark to a degree.

    ... Steve
  6. retromike3

    retromike3 Member

    Death by starvation

    I don't know if its the best idea to always kill the motor by starving it of fuel. these are two cycle motors after all and no fuel means no lubrication. I can't be certain if this is the proper way or not but I have had no problem lately with using the white wire hooked up to the built in kill switch on the throttle.

    I did replace my throttle/kill switch a few months ago because not only was it shorting out, but it finally wore to the point of braking into pieces. I ordered a new one from BikeBerry and it has worked well since then.

    I now have zero parts that came from my original kit I got on ebay. On the other hand I think of it as a one hundred a fifty dollar (including shipping) coarse in two cycle motor bicycle mechanics.Thanks to this sight, I can now rebuild one of these things in about an hour if I am not too distracted, although I have yet to take apart the lower end/transmission yet but I still have a spare one to rip into just to see how these things tick.

    Mike Frye the bike guy.
  7. 210061741

    210061741 Guest

    Well it has been said around here that shorting the magneto to kill the motor may take some life away from it.

    Putting a switch on the blue wire dosen't short anything out.
    Better for the magneto.

    Like i said i like to fully choke my engine and give it full throttle.
    Running it out of gas has to be harder on the motor.

    No lube when it runs out of gas and also no lube when you start it back up.
    The cylinder is dry.

    Maybe only momentarily but i'm sure after time it has some effect.
    Choking it floods out the engine keeping things nice and lubed up.

    But that is only my opinion and my bike stays outside.
  8. Dr. Doom

    Dr. Doom Member

    Does anyone with a good mechanic brain know if this can hurt the engine or carburetor or anything, in any way? This might be the best/most healthy way to kill the engine, from what I think. But on the other hand I’m just some kid. -I haven’t taken any mechanic training courses before-

    And what’s up with this about kill switch and magneto? I've never heard this shorter engine life theory before. How’s the kill switch bad for the magneto?... let alone when it’s connected to the white wire? I’m curious
  9. 210061741

    210061741 Guest

    The kill switch dosent hurt motor life.
    Thats not what i was saying.

    I was saying it hurts the life of the magneto.
    If you search "NO SPARK" on this forum you will find out the details of the Blue Wire.

    Other members have had alot of troubles with the magnetos and the Kill Switches.
    They decided it was better to disconnect the kill switch " White Wire " and run only the blue and black to the CDI.

    Normally the white wire when you press the kill switch shorts out to Ground the green wire from the throttle.

    So you are actually shorting out the magneto to kill the motor.

    Now a switch on the blue wire just connects disconnects power to the CDI.
  10. loquin

    loquin Active Member

    I think the problem with mags going bad is just that... bad mags.

    Shorting the mag should have no effect on it, unless you were coasting down a mountain, and held the switch closed for miles.
  11. arceeguy

    arceeguy Active Member

    The kill switch on most small engines shorts out the stator (magneto) to eliminate the spark. It does no harm.

    I favor the white wire rather than the blue wire because I'd rather have low voltage at the kill switch rather than the couple hundred volts present at the blue wire. Doubt I have seen a stator or CDI failure from it.
  12. tskrem

    tskrem Member

    How did u 'disconnect' your white wire?
  13. jimraysr

    jimraysr Member

    Siezing An Engine?

    I recall a buddy telling me that they made sure their go-cart engines didn't run out of gas as sometimes the little 12K reving machines would sieze before it came to a stop after running out of gas? 2nd hand information, but IT did make sense to me.


    DJEEPER Member

    Well, in a way, yeah that can make sense.. but you dont want to flog the heck out of the engine before shutting it down, you want a nice cool down period.

    The reason your buddy said that is because in 2 strokes, the oil is in the gas, so when you run out of gas, you will run on very thin to no lubrication for maybe 100 revolutions. Hot piston/engine plus no lubrication = seize.
  15. jimraysr

    jimraysr Member

    2 Cycle Seizure

    I have had my share of piston seizures. My first trail bike was a new 68 Yamaha 80 premix. Bright yellow, not pink. ) Really just a step through with a big rear sprocket. It was a good bike to learn mountain side trail riding. After doing something stupid the step through allowed me to extricate myself with out falling down a hillside occupied by boulders and cactus.

    Anyway my 200+ #s gave the engine a hard time and I seized the piston more than once. Would pull the jug after it cooled and clean up the piston and cylinder with crocus cloth. It allowed for an appreciation of the wonders of nature in total silence. My buddy rode a Honda Trail 90, so he was always there to save my back side. Towed me back to camp once after I slipped the rear tire and pulled out the tubes' stem.

    Back to the subject. All of those bikes killed the engine by shorting the mag to ground and I never heard of any problems resulting from the operation.

  16. AussieSteve

    AussieSteve Active Member

    Yep. Although these little engines are poorly engineered, they're fairly well designed. (I couldn't count how many mowers and other small 'stationary' engines, as well as small bikes, do it this way.)
    We can safely assume that the engineer who designed the electrics knew what he was doing. (But I'll bet he didn't intend it, (the white wire), to support lighting. It was only ever intended as a safe, low-current way of shorting the ignition.)
    As far as seizing an engine by starving it, that's very unlikely unless it was already very overheated and about to seize. (That's how they run those go-karts - right on the edge.)
    ... Steve
  17. Chunked my kill switch

    I was just comming to a stop then letting the engine die releasing the clutch til a friend mentioned choking it. I like the choke method it also seems to be easier to start without using the tickler on short stops to shop ect.
  18. arceeguy

    arceeguy Active Member

    Engaging the clutch at a standstill is another method to kill the engine. Once again, no harm.

    I would refrain from using the choke though. Although many believe this provides extra lubrication, it does not. The unburnt gas/oil mix has about the same lubricity of raw gasoline, it'll actually wash the cylinder walls of lube. Two strokes get their lube when the fuel vaporizes in the crankcase of a warmed up engine, leaving the oil to coat the internal parts. (I also think their is some centrifugal separation from the rotating parts, but don't quote me on that)
  19. Bent Spoke

    Bent Spoke New Member

    Leaning it out by starving it from fuel is about the worst thing you can do, the idle goes up just for that, your leaning it out. I use the kill switch that's why its there.
  20. I thought the kill switch was to hide your motor running from the cops.
    Why U say starvin it from fuel that's the opposite of what the choke does? Explain why you think something matters and I might listen.