Key Switch with led

Discussion in '2-Stroke Engines' started by atomichurley, Dec 10, 2009.

  1. atomichurley

    atomichurley Member

    I was wondering if anyone has mounted a key switch to their bike i was also thinking of mounting it into a small plastic/metal box. I would also like to have a green led for when the switch is engaged.

  2. AussieSteve

    AussieSteve Active Member

    I just drew up a quick circuit that should work. The only problem is, I'm unsure of the exact output voltage of the blue wire, so the resistor value will need to be trial and error.
    I've heard that the voltage may be as high as 120V, so for R1 I'd start with a 6K8, 5W (ceramic) resistor, then work down in resistor value until the LED brightness is about normal. Stick to 5W resistors, though, or they'll get too hot.
    eg 6K8, 5K6, 4K7, 3K3, 2K2 etc. They cost 20 or 30c each at any electronics hobbyist store, so buy 5 or 6.
    If the LED looks really bright, stop the engine and change to an even higher higher resistor value.
    If the resistor value is way too low, the LED may fail or the engine might not start. That's why it pays to work down in steps.
    Don't worry if the resistor gets a bit hot - that's normal
    Typical average LED current is supposed to be about 20mA, if you have a multimeter. An analogue meter or 'True RMS' DMM would be best for this. Otherwise, just go by brightness, but don't try to light a normal green or red LED 'super-bright' - it will fail.

    N.B. It could be done better using the white wire, but then you'd need an ignition switch with normally closed contacts, that open when the ignition is 'on' - probably hard to find.

    Let us know how you go.
    ... Steve

    The circuit:-
    (The resistor, R1, limits current through the LED to a safe level and the 1N4001 diode, D1, prevents the high reverse voltage from damaging the LED when the polarity of the blue wire goes positive.)
    - Just noticed, in 'Parts' below, I said start with a 5K6 resistor, but a 6K8 as mentioned above is even better for the first test... S


    Attached Files:

    Last edited: Dec 10, 2009
  3. I've used keyed kill switches on all my MBs to deter theft. The kids in my neighborhood all want to steal my bikes for joy rides so I make a big display of using the key. I also mount the switch in a prominent position on the top tube just behind the steering tube or on the handlebar mount so it is quite visible, obvious, and convenient. So far it has worked (crossed fingers).

    You can use the same switch as is used in millions of riding mowers, snow blowers, etc, but they all use the same key, so security is questionable. I have bought keyed switches from an electronic supply house. These have a more complex key and many contacts, some open with the key on, some open with the key off. Use an ohmmeter to find the contacts that are closed with the key off and open with the key on to act as a kill switch. I mount the switches in two 1 1/2 inch PVC pipe caps glued together. Since these switches are not made for outdoor use I seal the whole thing from the elements as well as possible with silicone gasket sealer in all holes and lube the key slot with water proof grease. I have used corrugated split plastic conduit to hide the wires and tie it to the bike under the top tube for a nicely finished look. I run two wires from the mag and back to the engine block for a solid ground. I have also used an 18 gauge two wire black extension cord, I think it looks even better and more "finished" than the corrugated conduit.

    Just drill a hole in the end of one cap, attach the switch through the hole. Drill a hole in the bottom of the other cap for the wires to exit along with a couple small holes for mounting screws and then use PVC cement to glue the caps together. You can then sand the joint smooth and paint it for a nice look. I don't use a light, the position of the key indicates on or off well enough for me.
    Last edited: Dec 10, 2009
  4. AussieSteve

    AussieSteve Active Member

    Although I drew up the circuit, I agree motorbikemike45 that a LED isn't really needed. Hard to see in daylight anyway, but good practice for me scribbling the circuit.
    What I forgot to say was that a key ignition won't stop a bike from being stolen anyway. They have pedals and weigh SFA.
    Keep those fingers crossed. I hope you use a chain and lock too.

    ... Steve
    Last edited: Dec 10, 2009
  5. Yes, I use the best chain and lock I can get. LOL!
  6. Al.Fisherman

    Al.Fisherman Active Member

    I have a speedometer, key switch, and LED on my bike. I got it off of a old non peddle scooter. I wanted it basically for the speedometer/odometer. I see no use hooking up the key switch for reasons above. You think a key switch will stop someone from stealing the peddle capable 40 pound bikes? Think again. Thankfully I live in a area that people leave your s**t alone. In the last 11 years we had 1 intruder into a house and they got caught. I could if so inclined leave my bike in the front yard, go away for days and it would be right where I left why put the temptation out there?

    Besides with $150.00 in one, it wouldn't be such a loss. Don't get me wrong. I'd be pi**ed. BUT I'd build not only another one but a better one. With each one they get better and better. You learn from each previous build, seeing that I've built 5 of them, working on my 6th.
    Last edited: Dec 10, 2009
  7. AussieSteve

    AussieSteve Active Member

    A speedo/odometer is a good addition, especially for the run-in period. Without it, I'd go about 10kph faster than I really should.

    Now, the real reason for my reply - the price of bikes and engine kits over there is amazing.
    Here, to buy off a decent dealer, a 66cc engine kit is just under $300 delivered.
    Then, I went looking for a second-hand or K-Mart bike - nothing to fit an engine, so $300 later for a new large-frame Malvern Star MB...
    Add a billet head at $100, 3L tank at $71 delivered, 40T sprocket, about $70 delivered, my gel seat, $81 delivered + more. Lucky I don't want to sell it.
    ... Steve
  8. Al.Fisherman

    Al.Fisherman Active Member

    Dang Steve...just bend over:icon_cry:
  9. AussieSteve

    AussieSteve Active Member

    Under other circumstances, I wouldn't like to hear that, but what can I say - that's what's being done to us in terms of prices.
    Delivery is BS, but that's UPS, not the merchants.
    Nothing much is available here except stock parts and Rock Solid Engines stuff.
    As a pensioner, although those prices are high, they still beat the cost of registration etc. for a car or motorbike. I need something reliable, though, and capable of a bit of range, hence the stupid spending.

    ... Steve
    Last edited: Dec 10, 2009
  10. I put a key on my bike. I went a little crazy and purchased a gas tank for my motored bike. I needed to buy a cap for it so I purchased a cap for a Honda Rebel 250 motorcycle. I am building a replica of an old Indian motorcycle so I'll be calling it an Andian. To give it that vintage look, I mounted the key system right under the seat on one of those rods that go down to the rear wheel mount. I used 5/8" clamps to hold it on. It came with wiring and everything. I just needed to clip the ends and mate it to my wiring from my engine. If anyone is interested, I can get some pictures tomorrow. Just let me know.
  11. I keep my bike in my bedroom and when i go to the store i use a bike cable lock.
  12. AussieSteve

    AussieSteve Active Member

    My electric bike is in the house, with 2 dogs, one a dingo/bull-terrier cross. No problems there.
    My 2-stroke bike is in a locked garage, with a DIY alarm fitted.
    I bought a cheap but loud alarm made for doors and windows. The main box is 2" x 1 1/2" and has an on/off switch. The alarm stays 'off' as long as a magnet is alongside the box.
    I glued 10' of cotton to the magnet and loop it over my tail-light. The cotton drops straight down and under a carelessly-left newspaper on the floor, then on to the magnet on the side of the alarm box. I leave the box turned on and the magnet in place at all times and operate the alarm by looping or unlooping the cotton from the tail-light. (I put the end of the loop out of the way when in the garage so I don't accidentally trip it. Too hard to get at it to turn it off.)
    The box is well hidden and would be hard to find quickly to turn it off.

    (Sitting here watching old 'Hogans Heroes' re-runs - good stuff.)

    ... Steve
  13. Here's how I hooked up my ignition switch. I just put it in line with the blue wire and didn't use the white wire at all.

    Attached Files:

  14. KCvale

    KCvale Motorized Bicycle Vendor

    Just use the White 7.5V .5A kill switch magneto wire for your ON light.
    But I agree, without a battery you don't need to know the thing is running with a light.
  15. Bryan Smith

    Bryan Smith Member

  16. AussieSteve

    AussieSteve Active Member

    Well, now that you have a keyed ignition, I guess your bike is safe from theft!!!
    If you're not using a chain & lock, you're risking having your bike stolen, with or without an ignition switch. They can just pedal off.
    If you are using a chain and lock, do you need a key ignition?
    Any thief would just pedal off, then sort out the hot-wiring later.
    Waste of time and effort, in my opinion.
  17. Thankfully, it wasn't your time or effort that was wasted. :grin5:

    I wanted a key to go with the theme of my bike and, it allows me to use the "kill button" for the horn. I like it and I don't rely on it to keep my bike safe. I have a lock for it also.
  18. AussieSteve

    AussieSteve Active Member

    Nothing wrong with a key ignition - just keep that chain and lock.
    Those b a s t a r d s out there will happily carry one of these off, if necessary.

    A couple of days ago, I had my electric bike chained to a post in the local shopping centre and got back to find three guys next to it, one crouching down pretending to do up a shoelace. (Guess what they were up to. And right in front of the bank and a security camera.) I'm glad I've got a hefty chain and lock. The electric bike has a key ignition, but it also has pedals, chain and gears, like our ICE MBs.