Bicycle Motor Spark Problem?

buttburn

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Feb 1, 2008
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Well I got my Starfire 48cc engine on my cruiser. Well I hooked the magneto to the two matching wires (leaving the white wire off.) I then hooked up the little button coming off of the throttle to the white and then grounded it to the frame, as a kill switch. Well I ran the bike, but it doesn't run well. Sounds like its not detonating right and the button doesn't work. Well I unhooked the button wire from the white and ground and the bike wouldn't even hit. Hooked it back up and it ran the same. I can only get up to about 10-15 mph WOT and I'm sure something's up with the spark. I also replaced the stock wire off the magneto with a performance one from Cruiser and used the NGK plug. Any suggestion? Is my plug gap wrong? My plug reads a light brown, so I'm thinking carb is okay?
 

Pablo

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Dec 28, 2007
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Re: Spark Problem?

Is the engine new? Or did you take it off a different bike? :confused: (was it running well before)

Sounds like a flaky connection in a way, but also sounds like wrong wire hookage.....are you sure the white wire is your huckleberry?
 

Ilikeabikea

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Jan 27, 2008
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Re: Spark Problem?

On mine the white wire is to run the lights. Mine has a blue and black wire for the ignition. But yours may be different...................
 

buttburn

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Feb 1, 2008
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Re: Spark Problem?

Brand new old stock of 2006 GruBee Starfire.
I can't be sure as of now since its dark outside with the bike in my barn, but from this picture it looks as if Blue going to Blue from Mag. Black going to Black from Mag. Red from throttle to White from motor. Other wire from switch grounded by clamp of Mag. I did have to put some electrical tape on the carb where it connects to the manifold to shim it because it wouldn't secure itself.

Pics:


 

Ilikeabikea

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Re: Spark Problem?

Hook the two wires from your kill switch to the black and blue wire from the coil. Don't hook the white wire to anything. It is for lights. I bet that will fix it.............
 

buttburn

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Feb 1, 2008
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Re: Spark Problem?

Hook the two wires from your kill switch to the black and blue wire from the coil. Don't hook the white wire to anything. It is for lights. I bet that will fix it.............
*slap* doh, man so the magneto doesn't have to run off any of the wires from the motor? What are the 3 wires from the motor for ?(I know that the white is accessory) So basically the wires from the magneto are for the killswitch? Although the kill button only has one wire to hook up (red) and a black that is a ground with a loop.
 

Ilikeabikea

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Re: Spark Problem?

I just plug the two kill switch wires in the connectors where the engine wires hook to the coil. When you push the kill switch it grounds them together and kills the engine. You can hook the blue and black from the engine to the blue and black on the coil and it will run. But then you don't have a kill switch.
 

deacon

minor bike philosopher
Jan 15, 2008
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Re: Spark Problem?

No the blue wire goes to the blue cdi wire and to the kill switch wire. It is a three wire bundle. The black wire goes to black cdi as does the ground wire from the kill switch. EVerything is wired to the magneto. Try that and see if it wont solve your problem/.... Sometimes the wires are not the same on the magneto and the cdi but black is always black and the other two are some other color. Just wire the kill switch to the cdi wires.

Also make sure the white wire doesn't get grounded by accident it will definitely kill the engine if it does.
 

buttburn

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Feb 1, 2008
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Re: Spark Problem?

How can I hook three wires together two males one females? The kill switch ground is a loop where do I connect that?
 

deacon

minor bike philosopher
Jan 15, 2008
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Re: Spark Problem?

I removed all my ends and just hooked them with a wire nut.

Heres how it works.

Kill switch is an open. In other words dead wire till you push the button. It is not in anyway effecting the operation of your engine. However when you push the button, it grounds the circuit before the power goes to the cdi. Which kills the engine.

One side of the loop goes to the hot wire from the engine and one side is ground from the engine (black)

On my engine anything I wire to the white wire kills the engine so I don't even use it for lights. it just hangs there. Matter of fact, I need to tape it off. One of these days its going to do a ground on me at the worst moment.

Ps. on my bike the connectors came apart I didn't lose anything by cutting them off.
 
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buttburn

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Feb 1, 2008
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Re: Spark Problem?

Okay thanks for elaborating. I think I understand, I just really don't have any knowledge of electricals. We'll see how it goes this afternoon once I get home. I'll let you all know. Thanks everyone for addressing my problem, this forum is very helpful!
 

deacon

minor bike philosopher
Jan 15, 2008
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Re: Spark Problem?

Do let us know what happens it helps us all when a problem is either solved or a perceived solution doesn't work. Don't give up no matter what we will keep trying.
 

paul

Well-Known Member
Dec 23, 2007
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Re: Spark Problem?

ya don't give up. the rush when the bicycle engine finnally fires up is worth the little set backs.
 

buttburn

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Feb 1, 2008
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Re: Spark Problem?

Didn't get a chance to take a look at it this afternoon, hopefully tomorrow. Deacon, what part of NC are you in? I'm out of Chapel Hill.
 

deacon

minor bike philosopher
Jan 15, 2008
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Re: Spark Problem?

High Point,

As for your problem, with these bikes its trial and error every time you start it. that the fun part. So if this don't work we have lots of other things to try.
 

bravofire84

New Member
Feb 13, 2008
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Re: Spark Problem?

yes i bet matching up ur blu to blu lk to blk and no white wire will do it mine ran good after that.
 

buttburn

New Member
Feb 1, 2008
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Well I had a chance to run the bike yesterday. Well I hooked the black to black and the blue to blue from the coil to the motor and unhooked the killswitch coming off of the throttle completely. The bike runs poor for about 1-2 miles then once I hold it WOT it will accelerate run fine. I have the old GruBee kit (2006) with the PREMIUM CARB which I haven't seen anyone run. It doesn't fit on my manifold with out using electrical tape as a shim. I'm thinking that the carb is too big and is only good for WOT runs. This is not good because I haven't run but a sip of gas through it and have had several WOT runs. Ah ****, I'm fed up. I did buy the Happy Time Carb and Big Intake Manifold off ebay this morning. We'll see if that fixes this. Any inputs guys?
 

paul

Well-Known Member
Dec 23, 2007
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if you have any air leaks around the carburetor and the manifold it will run poorly and that's what it sounds like to me but i am no expert and still learning. a way to check this is if you can get it to idles spray a little starter fluid on the connections where the carburetor connects to the manifold and if it changes you have a vacuum leak. i know it is discouraging but is worth the time and effort you put into it. we all had problems getting our bikes to run properly and it was frustrating as heck. when all the little bugs are out of it you will look back and laugh at what it took to get things right and smile big time as you ride