Kill Switch Help

Discussion in 'Electrical' started by iFixEverything, Jul 12, 2011.

  1. iFixEverything

    iFixEverything New Member

    Hey, so today I just finished building my 49cc motorized bike. The one problem I'm having is with the kill switch wiring. Two wires are coming from the kill switch one is black and the other is yellow. The ignition has a blue and black wire and the engine has blue, black, and white wires coming from it. Can anyone help me with connecting the black and yellow wire to? Thanks

    Attached Files:

  2. ferball

    ferball New Member

    Hook all your black wires together, then hook your blue and yellow wires together, by together I mean twist all three into an ugly clump. Ignore the white wire. The kill just shorts the two ignition wires when pressed.
  3. iFixEverything

    iFixEverything New Member

    spark plug will work or not?

    hey, I just ordered a kit and when I got around to the spark plug I noticed the tip of the plug was missing(the thing that screws on I dont know what its called). I was just wondering if it would effect the engine? Thanks-Sean
  4. Al.Fisherman

    Al.Fisherman Active Member

    First off throw that plug away...Get a NGK or the equivalent, just not Chinese. Second to answer your question, the plug cap fits on a spark plug with no tip (just the threaded stud). Also get a good wire core plug wire with a good boot. Rob off of a ole lawnmower or a lawnmower shop can supply them.

    Before you get the cart before the horse, he's some items that need to be looked at.

    These are the things that I do, I see that others such as the seals (which I've never had one go bad) mentioned. All these mods or replacements are most likely less then $50.00. Choose what works for you, ignore the rest, but here you have them.

    1. Unpack engine
    2. Check for any missing parts
    3. Remove head
    4. Mill head (flat glass and 230 (or finer) grit sand paper. Rub gasket surface to insure it is flat. Check the cylinder also.
    5. Tap cylinder stud holes to insure they are taped to the bottom.
    6. Discard all studs and nuts.
    7. Replace studs with Metric 8.8 (US Grade 5) Replace nuts with locking nuts. 8mm studs are either 1.0 or 1.25 thread, 6mm studs are 1.0 thread. 8mmX1.0 is not common, but I have 1 engine with them.
    8. Replace spark plug with a NGK or the like.
    9. Replace spark plug wire and boot (check with lawnmower supply) or rob from old lawnmower. Use wire core lead.
    10. Mount the engine properly, no gaps between the bike tubes and engine mounts.
    11. Torque 8mm to 150 to 200 INCH POUNDS
    12. Torque 6mm to 60-70 INCH POUNDS
    13. I install cylinder studs with lock tite, and let set overnight
    14. I coat the head gasket with Copper Kote
    15. May need to bend exhaust pipe for crank or frame clearance. Recommend using heat.
    16. Remove or cap magneto white wire off.
    17. Re solder blue wire on magneto.
    18. Make sure all wires have a good connection and use tape or better yet heat shrink.
    19. Hook up kill wires AFTER you get engine running.
    20. Try not to drill holes in the bike frame.
    21. Do away with the clutch cable routing; there are a number of options.
    22. On my kit the rag joint had gauge (Metric) 8.8 bolts, If not replace them. I replaced the nuts with lock nuts.
    23. I sealed the wires coming from the magneto out of the engine with RTV.
    24. Place a “O” ring in the carburetor throat.
    25. Some say replace the axle with a better one. Never had a axle bend on me.
    26. For coaster brakes…Some say trim the cap, but I don't like it. or a file of sorts can be used.
    Last edited: Jul 13, 2011
  5. iFixEverything

    iFixEverything New Member

    Running out of options

    hey, so I received my 49cc engine tuesday. I finished the build and had to get my chain cut. once I put the chain back on with the master link and tried to start it I noticed the top of the chain was connecting(hitting) with the bottom chain when pushed forward and also the drive sprocket would not move. I believe something is wrong with the clutch setup. even when the clutch level is disengaged or engaged it does not move, its a spring loaded push button lock clutch. i hate how the pdf directions are just 2 words with a horrible picture. please help guys i just want to be able to take this baby for a ride!
  6. Al.Fisherman

    Al.Fisherman Active Member

    I don't understand.. you cut the chain, and now it's still too long that the upper and lower touches???
    As far as the clutch, it may be stuck and needs adjustment. Remove the clutch cover, flower nut screw, and turning it in or out adjusts the clutch. There are other fine adjustments on either end of the cable.
  7. iFixEverything

    iFixEverything New Member

    Also done

    after coming real close to a near death experience i will not go back on my bike til these problems are fix:

    main problems:

    bike is also always moving and it wont come to a complete stop. it like it has no clutch( example: like a goped)

    kill switch decides when it wants to work; kill switch only works when im going less than 5mph

    when throttle is closed engine starts to stall and pull back

    overall the engine is not working correctly. it sounds weird and only feels normal when going 20+

    I have my tool kit out and i appreciate any suggestions.

    Thanks- Sean
  8. motorpsycho

    motorpsycho Active Member

    It sounds like you have no clue as to what you're doing.
    Based on your name (ifixeverything) it sounds like you are a master mechanic. The things you are having problems with, you sound like you don't have ANY mechanical experience at all. I don't mean to sound rude but these things are SIMPLE and if you are having this many problems now, What are you going to do when it comes time to fix it when it breaks? What are you going to do when it comes time to tune the carb so it actually runs right? I know that people have to learn somewhere and at least you're here asking for help. but, coming in with a name like "ifixeverything" is kind of funny.

    For your wiring, when you get it all wired right the way Al said above, solder all of those wire connections together and cover them with heat shrink (or electical tape at the least). Get rid of the push together connectors because they're junk and they will break. If ANY bare wire is touching anything metal, you'll lose spark and the motor will run like poo.

    Sounds like you need to adjust your clutch because the clutch should work just like a motorcycle clutch. Handle pulled in, bike will not move and you can rev the engine up like you're in neutral. Clutch lever out, bike will move with plenty of power and no slipping from the clutch. You can actually feather the clutch on take off like a motorcycle to get the bike going. If you just dump the clutch (let the handle fly out of your hand on take off) the engine will die.

    With the throttle closed, adjust the idle screw on the carb. in until the engine runs on it's own.
    If that doesn't do anything, check to make sure that you have the throttle slide in the carb the right way. It can go in 2 ways but only one way is right. If it's in wrong, you will not be able to adjust the idle, and it may be bound up and stuck at 1/2 throttle or wide open throttle.
    Pull the throttle slide out of the top of the carb and look at it. You will see that there is a long slot and a short slot on the throttle slide. The short slot goes to the left(when looking down at the engine sitting on the bike) and the long slot gets lined up with a pin that's cast inside the carb. body.

    As for your chain, you'll have to post some pics. Putting one of these things together isn't a 3 hour job because you have to be prepared to modify things to make them fit. Getting the pedal chain and the engine chain both tight can be a trick. Normally you'll get one tight and the other will be too loose. if your chain is THAT loose to where the top of the chain is hanging down and touching the bottom of the chain, it's way too long.
    You will have to take the master link out, put the chain around both sprockets, and then pull the chain together so that it's somewhat tight. then you can mark the link(s) to be removed. You can grind the heads of the pins off of the link that you need to remove if you have a grinder or a dremel. and then just punch the pin out with a hammer and a punch.

    Like I always say, if someone is expecting to assemble a motorized bike and be riding it in a few hours, they have no idea what they're in for.
    These are the situations where poor assembly leads to the builder coming back saying how much of a peice of junk the engine and kit is.
    Hopefully you have replaced the rear sprocket lock nuts, bolts and washers with better quality ones and you are using blue loc-tite on every nut & bolt.
    Last edited: Jul 14, 2011
  9. BoltsMissing

    BoltsMissing Active Member

    OMG, this is going to be one of those threads...back to the very basics

    Kill switch---for now, forget it, just join the 2 wires from the engine to the CDI black on black, blue on blue, insulate properly. Forget about the white wire, make sure the ends are snipped, insulated and tucked away so it don't touch and metal.
    If you got brakes, it will stop.

    Spark plug, as mentioned, get the NGK plug ( B5HS will do for now )
    Get a plug Cap while ya there to, NGK have those also, don't have the part number right now.

    Clutch seems to be your major issue for now.
    Ya gotta figure it out, search on the forum for pictures, but I'll try to explain, ( still can't find this darn camera of mine)

    Remove the right side clutch cover.
    You'll see a star nut, it ought to have a lock screw. Remove the tiny lock screw.
    Wind in the star nut 1 notch at a time. Pres the clutch lever on the handle bar, but make sure there is no slack at the other end of the cable first.
    When you bike wheel starts to roll freely, ya about done...fine tune the adjustment, you will feel if it's ok..
    Keep checking the cable at the other end cos it stretches, before you make any more star nut adjustments.

    Try that and see how ya go.

    Post pictures, we would like to see you everythingfixed builds !

    Other stuff
    It is commonsense to the eye, carburetor to manifold air leaks, gasket shape mismatch
    Exhaust flange leaks...same, gasket shape mismatch...,
    look at it and just simply fix it.
  10. iFixEverything

    iFixEverything New Member

    i've fixed the spark plug and checked the gaskets and carb. the only problem is that the bike doesnt want to stop it keeps moving. the only way to stop it is by using the kill switch. once it starts going it keeps going and
    does not want to idle and when its at very low rpm its very sluggish . i believe it has something to do with the carb but i dont want to mess
    with it till i know what to look for.
  11. BoltsMissing

    BoltsMissing Active Member

    Clutch adjustment ?
  12. iFixEverything

    iFixEverything New Member

    should i make it tighter or loosen it?
  13. retromike3

    retromike3 Member

    You might take a look at your clutch

    if your clutch cable it a bit too loose, even when you have "pulled" it in the bike will still want to "walk" foreword. Happened to me on my latest build. I finally fixed it by changing the clutch cable from standard brake cable to Indexed derailleur cable housing. There is quite a bit less flex in that housing.

    just a thought, Mike
  14. HeadSmess

    HeadSmess Well-Known Member

    you cant mess the carbs up. theyre waaaaay tooo simple for that.

    clutch. pull the bleeding cover off if theres a flathead screwdriver in this tool kit of yours. look at it. if it doesnt suddenly appear bleedingly obvious whats wrong...change your name!

    asking these sorts of questions with that sort of username will only result in ridicule!
  15. motorpsycho

    motorpsycho Active Member

    I already explained what to look for in the carb.
    it sounds like you have the slide in wrong.
    also check that your choke is opening and closing all the way and that you don't have it closed while you're trying to ride.
    I still think that you have your clutch way out of adjustment.
    you should be able to tide your bike like a motorcycle using the clutch. man if you can't figure out how to adjust a clutch, what can you do?
    adjusting a clutch is pretty much common sense for anyone who knows anything mechanical.

    what do you mean the only way to stop it is to use the kill switch?
    do you mean to stop the engine, or to stop the bike from moving?
    if you can not get this engine / bike to work right i suggest that you forget the whole thing.
    paret of building/ridingone of these things is trying to get it to work right and tinkering with it.
    if you were expecting to get a kit, slap it on a bike and be riding 3 hours later, you must have been dreaming.
    Last edited: Jul 15, 2011
  16. HeadSmess

    HeadSmess Well-Known Member

    i happen to have bought the time down to 32 minutes :) all are welcome to follow in my footsteps but be warned...its hard! you gotta have all them tools laid out neatly and have a nice stiff drink close at hand...