1978 cb400a CDI interchange

[hypnotist]

Ok I need to know.. is it possible to interchange the CDI fron another cb400 bike to the cb400a. I have several cb400a cdi boxes and an't seem to get a spark. I  assume it is the cdi box being defective. Is there any way a cdi on this bike can be tested? I have bought several used cdi boxes at a very inflated price and am about to junk  the bike and part it out and sell the components on e-bay

[carlosvaras]

Hey

I'm having the same problem on the same bike. I got a new coil, plugs, wire caps, battery and rebuilt carbs but the damn thing sputters at 30mph and won't go over. I suspect either the stator or the CDI. I think you can interchange them but not sure.

in answer to your question the only way to test is to swap it out for a different one (new perferably) and see if that did it. Where did you get the CDI's from? I believe the company that makes them in the states in Shindegen. You can google them and call to find out dealer info.

Hope this helps.

Carlos

[s2airflow]

I made enquiries re this only to find that although there are people building new CDI units,no one did the Auto ones.I was told to change the entire set up for the 400T spec,plenty of those about.Saves junking the machine.Dave.

[dunboyne]

they were buggers for corrosion on electrical connections .id check them thouragly first. i had many cb400a,cb400t,cb400n and the 250s too and neaver seen a cdi give up. i lost spark several times due to crap connectors and bad wiring though.