I don't have either a 169 nor a 1650, but I would agree with Don, that the 16HP elbows are bigger.
Here is what my research has found. There are two exhaust elbows that look very similar. Here is the difference.
KH-47-054-01-S was used on engines from 10 to 14 HP
KH-45-054-04-S was solely used on K & M series engines for 16 HP