Could anyone give me some ideas why my Kazuma 250 seems to eat CDIs? Example: Starts first try ( no long cranking ) and will run great. Then sometimes after days of being fine it will run poor and or die. sometimes it will run after sitting awhile but does it again. This has happend so many times that now i just replace the 10 dollar CDI and ride it untill it happens again. it was given to me because it didnt run, i found the CDI melted. This makes me belive its always been an issue. It really does run good with the CDI working fine but it becomes a pain when your on a ride and she dies. Just never know when it will happen. Can anyone give me an idea what could cause them to fail so often. Thank you

 

This seems to be the week for really weird problems showing up in this and the Kid Quad forums...

So where do you get your replacement $10 CDI's? Do they all come from the same place? If so, what I'm wondering is if your sole source has a truckload of bad CDI's that fail after running a few hours. There has been a few other threads over the last few months about people buying bad CDI after bad CDI from the same source.

Another possibillity: If your ignition coil arcs back internally to the ignition coil primary drive pin it could also take out the CDI. I wouldn't expect this to be a "run poor and or die" scenario, but rather a "run fine then poof-dead" scenario - especailly if it goes 'poof-dead' at high speed. In any case, if you can't find any other reason for the sudden failure of the CDIs then it would be reasonable to shotgun the problem with a new $10 ignition coil as well.

Is your CDI DC powered or AC powered? Do you know? An even more remote possibility is that your CDI is DC powered, and the charging system is going ***** to the wall and raising your battery voltage to something like 22 volts - which overheats the CDI and causes to fail when running at high speed for a long while. But if so you would notice that the battery is always running out of water....

 

thanks for the ideas. dont belive its the over charging issue you had mentioned. i have had no batt issues and have a volt meter on it. the other possible with buying bad CDIs is slim only because i have tried not only from different suppliers but also 2 different makers. guess were left with the coil. It really is odd. i can hold it wide open for 5 min on flat ground and it runs smooth, next trip at wide open it may run smooth 1/2 throt and buck wide open. same with idle, idle for 2 hours fine, then ride for an hour and let idle for 10 min and it will die. always if you let it sit and cool down it starts right up. sometimes run fine for a few trips before acting up again sometimes need a CDI. if i get it right i'll let you know and if i dont i'm sure you'll see another post from me

 

Your symptoms don't really sound like a series of bad CDI's. Have you tried putting one of your old CDIs back in when having trouble? Does it work at all? Are all your old CDI's flat dead, or do they all exhibit the same vague and variable symptoms? Usually when CDI's fail they fail big time. You get no spark. Dead, dead, flat dead...

Bad electrical connections can cause symptoms like you described. Vibration can make vital electrical connections intermittent leading to periods of working great versus not working at all (and in between). Then you change the CDI which wiggles the wires that are the problem.... This is a possibility to consider.

Ignition coils and spark plugs can have corona discharge that comes and goes. This is a possibility too, though usually these problems occur only at high speed since that is where the voltages involved are highest.

And it could be fuel issues too...

The main question I have is if any and/or all your old bad CDIs work at all if reinstalled. If they do I would lean strongly toward your CDIs not being bad in the first place and that we need to look elsewhere.

 

you know the loose wire or bad conection is a good possibility. like i said when i got it, the cdi was melted so i always point the problem towards the cdi. i was told ( by someone whos just a back yard hack as my self ) that the cdi can give you really odd problems when bad ( guess they and me were wrong ). and i have a habbit of over looking other things when i get something in my head. on that note i had to make plugs for the cdi ( that had been melted on factory harness ) because i cant seem to find the 4+2 ( 6 ) pin molded plugs for the cdi. without buying a whole new harness would you know a company that sells a repair molded end? i had asked the company i ordered the cdi from, when i first replaced the cdi and they said i needed the whole harness. tryed radio shack, and simular electronic stores who has alot of different repair ends but the plug is just not common and the terminals are so thin i cant even get insulated solderless ends to push on. any help on where to find this would be great and thank you for your help this far

 

I've looked too for mating connectors for CDI's. I haven't found any yet. You could always just buy your own connectors and solder short pigtail wires to the CDI pins (which then go to your new connector set). Or just solder the wires directly to the CDI pins.

 

well i went through the conectors and found some poor conections. i went through carb and found the electric choke ( inricher ) not working properly, seems to hang up , runs too rich, smokes, ect. i did some reading on the inricher and the problems that come up when they fail. i have (this time) exactly what i read happens. who knows if it has been the same problem but intermittently. i read that there is a company who makes a manual choke to replace the electric one. if anyone knows about this retro kit please let me know. thanks for the help