Coil grounded out

ok I swapped out a good coil from a running 450 and put my coil on it and it ran good. Can someone please tell me why i have no spark all of a sudden, my 400 was running great I was riding it and it died now I have no spark?

Check to see if coil went open with multimeter. Should be able to get a ohms resistance in manual. If that is problem be happy with simple fairly cheap fix.

Coil not open I have a running 450es is the cdi the same as a 400fm

Coil ohms out at .07 it’s in range

See if you have continuity from the spark plug wire, and the spark plug itself

I do

Think I read somewhere that these guys where putting in oven and baking out the moisture then they start working again. You would need to smear calk over outsid of coil to keep from happening agian. I would buy new OME coil so not stranded if option. Google the oven trick.

It’s not the coil I swapped out a good one from a running bike and still no spark

Can the recitiver cause a no spark issue

I would not know where to start on electrical problem like that. If not the kill switch on handle bar it could be anything. I would download shop manual and fallow there trouble shooting guide.