Yes, you're crazy. But aren't we all?
1 h 40 min is plenty of time at HEL. There will be nothing to slow you down – you enter the gate area and can just walk to your next gate. No immigration, no security, no passport control etc. Only a stand arrival and the need to take a bus would take some extra time, but even if the incoming flight has a delay of, say, 60 min, you will be just fine.
You could of course look at past data to see how often the AGP-HEL flight has significant delays.