Good ole ZX50

[jaxbeachjohn]

So i have the great ZX50, that has burned up 3 CDI units, countless hours of my time and a lot of frustration.
Its the same problem where you think its the CDI,but its not.!! So you go buy a new one and put it on.!...... Runs for about a day then does the same thing it did before! So im done buying CDI's!!! Has anyone put a end to this problem with their ZX?  Please help me!

 All new fuel lines, fuel filters, carburetor, exhaust. 

P.S. When this problem occurs, you can turn the red kill switch off and it still runs! hmmm

I give up, I need help!!! ha

[Shaka]

Check the voltage regulator/rectifier.  I have replaced mine twice.  I thought it was the CDI each time.  What are your symptoms?  Mine starts to stutter at about 1/2 throttle on up.  It would also cut out at WOT occassionally.  I would slow down and it would kick back in.  The regulator fixed this problem twice.  However, that problem solved and it just started hitting about 42mph and seems like it just runs out of juice!  This with a 70cc big bore, should go much faster!  I'm now wondering about the CDI as the culprit.  That's why I'm curious what exactly yours is doing.

[zombie]

Hi, I sent the info. on the cdi to your box, before i saw this post. There is obviously a problem in your kill switch. Trace the wires ALL the way back, and disconnect them at the source. I'll look at mine tomorrow nite , and post the easiest way to get at them

[jaxbeachjohn]

shaka
after letting it sit over night it runs good for 10-15mins sometime!!
As soon as everything warms up it starts running horrible! It still runs but it might do about 15mph and something it wili cut in and out! It will only idle for a second then cut off. At that time it wont start again! i have to put a different cdi on it and it starts right up!(ALL MY CDI's ARE SHOT) then it just runs like ass again! ive put new regulator on it! still screwed!!!!! did you have to change anything in the flywheel?like the stater or the coils inside ?

[Shaka]

I got the bike used with about 3000 km.  Shortly after I got it, I started having similar issues to what you are describing.  I took it back to the shop I bought it from and they replaced the stator and regulator, maybe something else.  I'm pretty sure they didn't do the coil, I'd have to look up the invoice to be sure.  I tried a new CDI before they did that work and it didn't help, that's why I took it to them.  And they traded the new CDI I had ordered for the parts I needed.  That took care of the problem for a few months, then it started doing the same thing.  This time not quite as bad though.  I only replaced the regulator and it was fine.  I replaced it with a used one the shop gave me, which I ended up just replaced with a  brand new one cause it was acting up again.  So far I am still on the original CDI with 12,500km now.  I think it would be worthwhile taking a look at your stator as a possible culprit.

[zombie]

Another possible is the stator. Bring an ohm meter w/ you and check the resistance when the scoot. won't start. If it reads a short, there it is. should read around a hundred ohms cold.