Volkszone Forum banner

2 STROKE Any ONE good With Bike's CPI SM 50CC wont start???????

15K views 19 replies 8 participants last post by  shytawk 
#1 ·
:confused:Hi

I know this is not the best place to ask but fort i give it a try,

I have a CPI SM 50 59 plate which has the AM6 engine in it

couple of weeks ago as i was driving back from school, the bike started to feel like it was miss firing and stuttered to a holt,

i then kick started it and drove off 2 min latter it just turned off,

i kept on trying to start it and it wont so i left it for a min and then it would start for 5 mins and i ride it but it would randomly cut out again,

im not too good with electrics but i checked the fuel line and fuel in the fuel filter and there was fuel, i changed the spark plug, iv checked if there's volts going into the coil, which there was i checked if volts where coming out of the coil (12v) which there was,-i dont realy know how to use a volt meter but i managed to get it say 12v-lol

but there is no spark from the spark plug, when i kick start it the front headlight lights up so the stator must be working and it does randomly start sometimes, i just bought a brand new coil which has made no difference and i don't no what the problem is, i cart seem to get spark, but it does randomly spark which then starts the bike

so im guessing there's something electrical wrong, as i think the problem is no spark

could any of you guys help me???

Thanks
 
See less See more
#2 ·
if the stator is working then it sounds like a bad conector somewere, recntly riden in the wet?
get you favorite water repelant spray out [dw40. duck oil etc] take each wireing conector of one at a time and clean them, pit back together and give them asuirt of the spray. also check for a brokien wire while your doing the conectors.
if that dont work then its time to start looking at at pick ups and cdi unit but that mostly means changing them for known good ones.
bike electrics can be a nightmere so good luck.
 
#4 ·
Thanks for that, Ya i did what you said and managed to see a tiny bit of carosion on some of the connececter but it didnt look bad, and still no spark, or very very week spark,

I put a negative voltmeter wire on the HT lead and connect the other end to the battery to see what reading i got which was normally 12v but as iv left the battery to drop its gone to 7v, but when i kick start it the voltage from the HT lead stays the same, but the front lights light up when i kick start,
 
#7 ·
Yep bought a new coil still no spark, or the rare tiny spark, I have a shitty volt meter just not too sure how to use it, I turnerned it left where it says something like 20 v and that show 12v from the battery and every where else on the bike, I had a look at Cdi and there looked like nothing wrong, but the volts never increases when kick started so I think it might be something with that, but from the coil it reads 12v even when I don't turn the ignition, would that help?
 
#15 ·
I put 3 difrent CDI units and still nothing, iv strippen the hole bike Cheacked everysingle flipping wire, cleaned them changed coil, and I still get a random spark, it's getting ne realy pissed off as iv spent too much money and time and now a feel like iv Cheacked a brick wall :/, my friend said it could be the black box the ECU but it's like £100 and I don't want to be wasting that kind of money
 
#19 ·
Hi, I don't think it's the stator as battery gets charged and the front light turns on when kickstarting, my friend said it could be the black box I think it's the CDI but he says it's the ECU, do you think that could be why it randomly sparks then cuts of, also I seem to be getting a very low voltage from the 2 wires going to do coil something like 0.7v but when I attach the 2 wires to the coil I sometimes see a spark and I get a big electric shock.
 
#20 ·
CDI stands for capacitor discharge ignition, and this is the pulse that is sent to your coil, it is very high voltage but super quick and can only be measured with an osciloscope, regular volt meters dont stand a chance. So i reckon if your cdi is working intermitantly its not the unit but the charge it is recieving from the stator, remove your flywheel (borrow a puller from a freindly bike shop) and check the solder joints of your ignition coil. It is common for these to give trouble because the engine vibration causes them to crack or seperate, re-solder all joints while you are at it, because sods law says the lighting coils will fail as soon as you put it back together. Hope this makes sense to you.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top