2 new bikes with same problems..please help!

gaspeddler

gaspeddler

New Member
Hello motorized bike community! I am new to this hobby and I am fairly mechanically inclined but when it comes to the details of engine/electrical workings I have a grasp of the basics...but I am really struggling with this one and hoping someone can assist. O.K. so i built my first bike and loved it so much I built another for my wife. These are new Raw motors 80cc engines with kill (my fun)switches. I have ridden them a few times to dial them in and worked out most of the kinks so yesterday my buddy and I took them on a real test drive to make sure they are capable and reliable before I ask my wife to ride one. Last weekend we rode them both for about 5 miles and they were great. Yesterday we took them farther...almost 20 miles or so round trip. They where running great and we were clocked by a roadside mph indicator going 39mph, could have gone faster if we new the indicator was coming up so we could "clock" our best time. Anyways they ran great until on the way back my buddy Trevor said his bike was losing power slowly, but I thought not to much of it as he was still hard for me to keep up with. We pulled into a predetermined gas station after a good 5 minute straightaway to check bolts and possibly add some more fuel, etc. Upon leaving the gas station his bike would not start. Just a faint change in tone as throttle was applied, but no power...then stall. He proceeded to walk/pedal bis bike for the next 2 mile stretch while I motored ahead, then waited for him. I thought I was real funny teasing him for having to pedal(only because his bike was faster all day...he also weighs probably 40 pounds less than me)only to have my bike do the same as his upon attempting to restart. No power to throttle, just runs during the wind down of pedaling to start, then coasting to a stop. Odd that they would both do the same thing within 2 miles of each other. Had to be install error, or bad parts on each bike(cdi/magneto?) or our fuel mix. So after a tough pedal back home I proceeded to drain tank and remix fuel and attempt to start...nothing. Then on a fluke I discovered something... First off I always wondered if I got the wiring right because I was told it was tricky and I never made sure it was "right": because the bikes worked so well it had to be right...right? I discovered that if I pushed IN the kill switch (as if to kill the motor) the bike would run again! Wish I discovered that while hoofin it home 5 miles! I looked through this site last nite and found a wiring diagram. I found that there are a couple ways to do it so I tried them both and still no worky unless kill switch is pushed! Not what I am looking for in a kill switch! Why is this doing this.. is it because I burned something out and only if I push the switch will it bypass the burnt out part and start working? My wiring is as follows: Black to Black/ Blue to Blue/ Green kill wire is grounded to frame (i tried to black wire also...no help) and yellow kill wire is to white (also tried to blue...no help)wtf? Any help would be greatly helpful as I would like to pinpoint this before dropping hard earned cash on guesses...thanks so much!zpt

ps- I haven't tried messing with the second bike yet but I assume it is the same issue as
problems where identical and proximity of timing was uncanny!
 
i dunno. just cap off the white wire and disconnect the kill wire. stop the motor using the choke.
 
The kill switch (button) is a simple normally open momentary switch. It should only close a circuit when the button is depressed. Your wiring is correct, or one of the optional ways to wire these 2 strokes, so I'm not seeing what's happening unless the switch has malfunctioned internally and acting in reverse of the way it is intended. Knowing how the switch is constructed I'm not sure how that could happen but if your description and diagnoses is correct it is the only answer that comes to mind. As the man above said, disconnect the kill switch completely, wire the black to black, blue to blue and cap and wrap the white wire then try the bike. If it runs, you've found the problem and most of the sponsors here will be able to provide you with a replacement kill switch if you desire to use one. As for the second bike, it will be interesting to see if the problem is the same. I'm skeptical unles your supplier just got a run of bad switches.

Oh, wait...If the black wire from the engine becomes disconnected from where it attaches to the magneto coil then you would be completing a needed circuit when you press the kill switch...Remove the mag cover and check the connections inside.
Tom
 
Tom-
Thank you for the response...I have tried disconnecting the kill switch as you said and checked in the mag. Disconnecting the kill switch made the bike not run at all...and the wires are connected in the mag and everything seems ok in there...and I just checked the other bike and same thing, power with kill switch engaged only! I opened up the kill switch this morning to understand it better and could see that it still connects the yellow and green when pushed in, as is normal I assume, so why would the green and yellow becoming a circuit power my bike? I have a metal strap securing the cdi to the frame and my green ground is sandwiched in there on the under side... could that be traveling through the strap and effecting the cdi? The strap does not come in contact with other wires at all. Has anyone ever tried pushing in the kill switch to see what happens when the cdi or mag goes out? I have to think that it is one of those two things... Side note: I was concerned about the last fuel mix ratio in the tanks and thought it might be off a bit...any chance that could have fouled the plug some and by pushing the button in instead of killing the motor it is giving more juice to allow an otherwise foul plug to spark? I am probably way off base here, but this is bizarre, especially when the bikes ran so good for about 40-50 miles. Also, the kill switches never really worked anyhow but I would like to have one on the bikes....
 
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Any chance the mag is wired wrong ?
not that i have done such a thing but have heard about things like that.
Nothing like a factory worker having a bad day.
 
Take an ohm meter and check the resistance of the blue wire.
It's posted around here somewhere what it should read.
I think its 300 something.
The white wire should read about 30.

Cap off the white wire.

Connect the blue coil wire to the blue cdi wire.
Connect the black coil wire thats attached to the coil by a screw to the black CDI wire.

Check for spark.

It will run fine that way.
 
This is one of the reasons why I don't like to see the kill switch wired as you have done it. I do not agree with grounding one lead to the frame and the other to one of the ignition wires (blue or white). Take a look at the diagram below and see if this will help you. The two leads (wires) from the kill switch should connect the blue and black wire when depressed via the switch contacts.

I've been thinking about your problem since yesterday evening and I have not come up with a logical explanation as to why the engine will run with the mag grounded and not run with it un-grounded. If this had happened from the first I would agree that possibly the mag is wound incorrectly but you've said the bikes ran okay for a while. That rules out that theory, at least for me.
Now you're saying the bike will not run even with the kill switch out of the circuit...Venice suggested trying to start it with the white wire grounded. I'd be curious to see if that works and if it doesn't, try grounding the blue wire then try again. I'd really like to see this one in person. Its a baffler.
Tom
 

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Thank you for the advice, now I have some ideas as to how to solve this. I will post the results and see if I can get some close up photos posted of the wiring.
 
thanks again... I will address this tonight and see if I can post some close up pic.'s Thanks all for the direction...
 
I'd try disconnecting the kill switch and checking the wiring between the ignition module and the engine. It's possible that a wire vibrated and chafed through grounding the module or heat from the engine might have melted the wire insulation somewhere. On my bike I grounded the green wire to the engine mounting bolt. If you ground it to the bike frame there's always a chance the electrical connection to the engine has some resistance due to paint on the frame.
 
Although it might not be the problem, I never trust the cheezy electrical terminals that come on the wires. If you can, cut and strip the wires and solder all the connections instead of relying on the very questionable plug in connectors.
You definately have a wierd problem on your hands.....
 
O.K. this is just a thought but maybe the winding in the magneto has broke and is touching the motor if this happend the motor would not run ,however if you were to press in the kill switch you are now completing circuit. One way you can test this idea would be to disconnect the yellow wire from wherever it is connected and replace it with a small piece of wire and grounding that wire .If the motor starts then you problem is in the magneto coil. Good Luck.
 
I wish gaspeddler would get back to us with what he's found. I'm really curious about this one. gaspeddler....you out there? Hello? Guess I'll have to PM him.
Tom
 
Hello
Well its been awhile since I could get back to the problem at hand as my wife is pregnant and hungry ALL THE TIME! I pre-made her a days worth of food so I could tinker. I found that if I grounded the white wire to the black, the motor would run, on both bikes actually! So I think the ground ineffective somewhere and that by getting the ground from the kill switch, the bike would run...? They both run great and I will proceed to redo the wiring with proper connectors and new wire. I also noticed a post recently (bluenosegoat-mag problem solved)about the mag ground wire solder failing and I wonder if that is my problem too...? These bikes are so much fun and it's great to have them running again, but I would like to fix the real issue as what I have now is only temporary and the kill switch didn't work with the white grounded ( at least how I had it wired ). Thanks for all the help and Venice your idea was right on...thanks!
 
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Gaspeddler,
It still doesn't jive. If you connect the black wire (the internally grounded wire from the magneto) to either the blue or white, the magneto should not fire. You are essentially grounding the circuit and 'shutting off' (actually diverting) the electrical current to the CDI. If you said you connected a wire from the kill switch to the black wire and the engine ran then I would say the internal ground connection of the black wire was bad and you were making a circuit around it through the bike frame to the engine case with the kill switch.
The diagram I provided is not clear in that it doesn't stress that the black wire is a ground. It is attached to the magneto core by a screw, actually one of the mag mounting screws. The white and blue wires are field windings, soldered into the magneto coils. Grounding either of them will kill the engine. The blue and black go to the CDI and are a complete circuit to the primary circuit of the CDI. The kill switch does nothing more than connects the blue wire, or the white if you prefer to use it, to ground. Keep feeding us information on your problem because it is one none of us have encountered before and we'd all like to know the answer. Thanks. Venice, any thoughts?
Tom
 
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