If your getting no reading from the secondary side of the coil, you have found your problem! Although, I find it odd that it runs at all..but "Stuff Happens"
As far as the module goes, I think size wise they are different, but if It does fit, Electrically it should work..all it really cares about is pulses per second from the magnetic pickup..
Would there be other signs if the chain had jumped? The engine always hesitates on WOT, and some times pops through the carb.
Depends on how far it jumped..It could go from the above..to a backfire on cranking, to no fire at all..That's why the need to verify everything is as it should be.
Go inside and stay warm..It's 75 and sunny here...