Problems with the ignition of the Yamaha XT225Serow

I have a Yamaha XT225 Model 1994 motorcycle, recently the induction coil was burned, because I was too expensive I made it rebuild it but it did not work properly, I took it to a different workshop to rebuild it again but it was the same. The motorcycle does not stabilize the minimum march, sometimes it accelerates alone to such high revolutions that in order to put the change to start it is necessary to turn it off, other times it becomes very dull. Is it that this coil does not admit reconstruction and it is essential

Look friend I think the problem is not in the coil rather, lava the carburetor and the chicler or air screw introduced or screw everything and then you return 3 complete laps these motorcycles work with a good air step I tell you why it happened to me the same thing when there is a carburetor of these motorcycles I leave them with that passage of air- I hope you serve you

Ok, friend thanks I'm going to do it and I tell you.