Scooterotica

Just rebuilt my engine put it back in the frame wired it up, but couldn't get it started i had no spark, so changed stator nothing then changed CDI no spark, then checked earths, all good but no spark , then removed CDI earth and hey presto spark and started engine. What the hell have i done wrong, i have checked and re checked all wiring from top to bottom and nothing out of place. :wtf:

Is it possible that the red and white wires are crossed, are your CDI's clearly and correctly marked as to which colour goes in where?

What make are the CDI's and did they come from the same source?

CDI is the one off the engine before re build and a brand new one not sure what make.The wiring has been changed round and checked

It's funny that,a mates did exactly the same.Connect CDI earth and it won't spark so he runs without it.

few years ago there was a batch of cdi's where the red and white terminals were wired wrong inside, you had to put red wire to white terminal and visa versa

wack 63 wrote:It's funny that,a mates did exactly the same.Connect CDI earth and it won't spark so he runs without it.

Thought about doing the same but worried about it going pete tong !! How did your mate get on ?

He's running it like that now and seems fine.Another little tip is if the wire breaks off the CDI is to piggy back from the white terminal to earth.