Yamaha PW50 no spark, ignition ?

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my67xr

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i thought of something else too,
are you still running the original Ignition Control box ?
sometimes they can fail and cause dramas.

it is mounted above the carby/airbox or below the back of the fuel tank and has 2 plugs, with 4 wires going in/out of it, and looks like this-





PW50 Wiring Diagram-

 

ricky_191

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Hi, thanks for your help mate. I got nothing on the black/red wire and I got 026 on the white/red wire.

I took the plug off for the white and red strip wire and stuck the prob in the end of the plug.

So does that mean the stator is gone ?
 

my67xr

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the black w/red stripe wire is from the Source coil, it is the Power for the CDI unit
it may not be dead,
it could have a broken wire between the end of the terminal, and the coil that sits behind the flywheel too ?

here is one of the cheaper ones on ebay, an Aftermarket complete stator for $82 delivered.-
http://www.ebay.com.au/itm/KDF-YAMA..._Parts_Accessories&hash=item2586668385&_uhb=1


i may be able to find one a bit cheaper too, but i'd need to make a couple of phone calls
 
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ricky_191

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so this red and black wire.. Could I trace it back to where it comes from and see if it's broken some where ? I don't really want to spend any more on this.

Thanks for your help.
 

my67xr

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the only way you could try, is to cut back the outer covering/insulation on the loom from the stator
carefully run a sharp blade down it, watching that you don't cut through a wire as you do it.
then about 25mm back from the terminal, stick a pin through the wires' insulation.
put your red lead from the meter onto the pin, and black to the frame/earth
if you don't get a reading, try another 25mm further down the wire, etc etc
if you do get a reading somewhere down the wire, then the break in the wire was obviously just above that.

if you cant get a reading, then the copper wire wound, source coil must have a shorted out winding.
 

ricky_191

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Could any thing else be wrong ? I have got a spark out of it but it's not all the time and looks pretty small. I will chase this wire back
 

my67xr

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so on the black w/red stripe wire, it read 1, same as with nothing connected yeah?


p;s did you end up trying your spare pitbike ignition coil on it?
 

my67xr

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have you tried putting the original throttle/switches back on and trying it ?
or even unplug your current kill switch wiring and try it ?

i'm only guessing here, but it sounds like the connections from the stator wiring to the loom could be dirty, and not making a good contact.

spray some wd40 etc into the stator wirings' terminals and plug it back into the loom,
then unplug it, and repeat this a few times
it may clean up where the plug/sockets touch ?


and you still didn't answer the question if you have the Ignition Control Box plugged in still too ?
 

ricky_191

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I went and had another look. In side the magneto there was this little screw that was loose and stuck to the magnet. So I spun that part around and I could see a hole next to the wire coil and the loose screw looks like the same size.

And I tested all around to all the contacts I could see and they all read from like 3-4 ohms. And one has a black wire coming from it and I couldn't see if it had a red stripe but it too read 2 ohms. I found the white with red stripe too.

So could this loose bolt be the problem ?

the cdi is connected but the stock kill/run switch and aftermarket kill switch have been taken off so they don't cause problems. Is the cdi the ignition control box or is there some thing else.. there isn't a spare plug free, only the one to the kill switch.
 

my67xr

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nah the CDI, and Ignition Control Box are 2 seperate things.

bingo, that loose screw sounds like it's your problem !!
if it is out of one end of the coil, the other end of the source coil will touch the inside of your flywheel, it wont be sending a proper signal up to the CDI.
it will also be damaging the inside of the flywheel, and the source coil too.

do you have a flywheel puller ?
it's the same as the one for a china Pit Bike.
M27 x 1mm, L/H thread
 

ricky_191

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lol could I just try and screw it in though the holes ? Would be hard but I don't have a fly wheel puller
 

ricky_191

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Ok, So I put the screw in.. wasn't that hard. I just taped the screw really tight to the screw driver and held the screw driver on the metal to brace it and got the screw started, pulled the screw driver out and then pulled the tape off and did the screw up.

I tested the screw I put in and got 3 ohms but still nothing at the black/red wire. All the points I can see in the magneto are all 3ohms.

Any more ideas. I'm guessing I need 3ohms on that black wire so cleaning the pugs ect won't help get power there ? I'm not sure.

Thanks for your help.
 

my67xr

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if the loose screw has turned around in the flywheel with the engine running, it may have hit the copper windings on the source coil.
if it did, then it may have broken/fractured a winding, or hammered a couple of them together, making it short out.
it could have also ripped the end of the black w/red wire off the end of the windings too.

i think you need to get yourself a flywheel puller, and check things out further.


the reading you need to see off the black w/red stripe wire, is around 300 Ohms
 

my67xr

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ricky_191

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Yeah I think it needs to come off. Is it worth buying one or just do it the really bad diy way. I might see if I can borrow a puller from the motorbike shop but I don't like my chances. If you don't have a super expensive big bike then you're not worth there time -_-

Thanks for your help mate. I will try and get the fly wheel off and see what's going on back there.
 

my67xr

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i took my IT200 to a bike shop ages ago, and got them to pop my flywheel off, they charged me $10 for 20 seconds work.
i went home and ordered one for myself off ebay.
very handy if you need to work on bikes/stators etc

the Yamaha IT200, PW50, Suzuki DS80, the Chappy, all my pitbikes, and a Mates RMX250 all use the same puller
 

ricky_191

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I might be getting a lend of one soon. I don't want to take it too the bike shop here because they are just not nice people. I will try to get a lend of a puller because I don't want to buy one just yet.

Also if I need parts for this, could i use stuff off the pit bike magneto since I have a few engines I can get parts from or would they be too big. Also could I get the crappy parts from a pocket rocket and try to make them work. Genuine parts just cost a lot of money and I really don't think it's worth spending more on this bike.
 

my67xr

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nah,
the Source coil from a pitbike wont fit (too big), and the 50cc 2T engines don't use one

get the Flywheel off first, and we'll go from there.
if the Source coil is dead i might be able to advise you on how to fix it yourself.
do you have a Jaycar shop close to you ?
 

ricky_191

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Hi, fail on getting the flywheel off. I'm going to take it in and get it pulled off. I tried a bunch of ways to get it off. I end up getting a puller but had to drill out the holes bigger and end up covering all the magnets in metal shavings and then I drilled them too big for the bolts I have and I need a bigger tap.

It's just a pain and for the $10 I really don't think it's worth any more of my time or money. It's hot and i'm over it lol.

So I will go and get it pulled off tomorrow and work out this problem and let you know how I go :)
 

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