1971 Evinrude 50 hp spark on only 1 cy coils okay

[Jeff the fisher]

I have a 50hp 1971 evinrude that won't start. I have spark on one cylinder but not the other. the coils were checked and tested okay.
I put on a used power pack that was supposed to be good. Any suggestions?
it also seems to lurch when it is cranking. Is that a power pack issue as well?

Thanks for any help