I have been working (rebuilding) on a roketa 250cc water cooled go kart,,
I'm just about done. Kart had a broken case for the 2nd time owner got discusted so left it to rot but other than that it was basically new and now alot newer..
It desided not to start but just once in a while it would and all good but next time same 'ol..
I went thru all the basics, fuel, power and grounds and such..
I'm thinking My problem is with in, stator not sending pulse to CDI all the time and has been just getting worse..
Today I read a post with similar no start.. With that input I went back and tried again.. I disconneted and hooked up My digital meter to blu and white(ground) and red and black(pulse) wires to stater.. I got nothing, I cranked motor and got .1 constant reading as cranking in ACV only.. Please help.. Thanks if You can!!,,

 

ok not knowing which type of cdi box it was I will still throw out what your facing. first off don't ever use a battery charger on anything higher then trickle. or jump starting it with anything running. the spike in voltage taxes the cdi box. it will start as occasional spark misses then the more it runs, the worse it gets until you shut it off and get nothing. BTW a week ago I knew nothing of these systems, thats how much effort I stuck into it since then and retained. Come to find out the cdi boxes have a thermistor in them that is very touchy when it comes to voltage and can easily burn up. its the same part that burns up in amps for cars when taxed or heated.

 

ok technically when measuring ac voltage there is no hot or ground. think of it like this, the stator creates ac volts then sends it to the cdi box. more then likely that is only a signal coil telling the cdi box when to fire. especially if there is a post ignition 12volt source going in and a ground. Every bike is different so it sounds as if your input is good as long as all the other wiring is good. you cant test the cdi box but you can test everything coming in and supposed to be coming out to determine if its good or not. especially grounds, some have there own ground, some input the ground.

 

Post this again in the chinese quad forum. Very little response will be received here for chinese quad (or buggy) questions.

 

Thanks.. My gokart running again.. I'm now thinking problem was caused by rectifier/regulator.. It is new but noticed when running voltage was about 17 volts, sometimes more and fried cdi. When I tirned on lights and volts dropped and kart ran better before total no start.. Today I put in new cdi and put old rec/reg back on. Volts read 14.8 max running and kart seems to want to zoom.. I'll see soon!..