CDI experts please help

[bhatch21]

I've still got my 88 250r that will only spark with a 400ex cdi. It has a new coil that fires with the 400 box and on my banshee. The bike ground is good, as are all the other wires in the harness. The connections at the cdi are not loose or corroded. The OEM stator and pickup ohmed out fine. Yet, it still wouldn't fire my CDI, a used OEM, or a NOS OEM box. I have no other bike to verify that all these are working though.

Since the wiring diagram showed that the only difference btw. the 400ex and 250r connections is the pulse generator ground, I figured mine must be bad. So, instead of buying a new one and trying to thread its wires through my existing stator harness, I bought a new Electrosport stator and pulse generator. After installing it on my bike, she still only fires with the 400ex box.

Since I've eliminated everything else, does that mean I have 3 faulty 250r CDI boxes?

[slamdak8782]

please show pictures of the coil you are using. Verify that you are plugging it in correctly it is color coordinated. If it is firing it is indeed getting a signal and thus firing from the pulse generator. Ground the green wire in the harness to the chassis somewhere. You can make a secondary ground off of any where in the harness with the green wire. Seems to be a strange problem. Ground it and plug it all in should work. If not id swap out all the parts and try with a different harness. Verify that you are using the correct tip on the spark plug can either be threaded or rounded. I have seen both. Pictures of ur cdi would be helpful to verify which you are using. I have atc harnesses on mine, fairly common. You could also remove all the tape and go over the entire harness to verify connections.

[slamdak8782]

Really shouldnt be this hard. There are only four wires comingfrom the motor. Match them with the color they go to. Is there a handlebar mounted ignition switch or has it been eliminated. Somephotos would help alot.

[slamdak8782]

You are not grounding the pulse gen ground are you this needs to go to the cdi not ground. Match the four wires that is all and ground the green wire this should allow it to work.

[bloodswet&gears]

Sounds to me like you have a 400ex harness. The plugs are the same but the pins may be in different places in the connectors.

Like slamdak said take a picture. A close up of the cdi connectors with the wire colors and location in the connectors.

Maybe somebody could get a pic of their 250r harness at the cdi and let you compare the colors to yours. I will try to tommorow.

[bhatch21]

It's a 250r harness. It was firing the HB9-CF552 cdi when I bought the bike. After 1 hr of riding, then no spark.

Blood, where are you at in tn? I'm trying to find someone with a running 250r that I can plug my 3 HB9 boxes into and see if they work?

[bloodswet&gears]

PM sent