must be different. i ordered a replacement cdi for the honda engine (granted, it was only a $10 from china on ebay) and the engine had no power. it started and idled, but would not push the bike with me on it.It all depends on timing from the flywheel.
Its not quite like you think, I have an older flywheel/ magneto combo that cannot interchange at all. The pickup is at the exact same spot with both. No mix/match can make it work right unless its the matched parts. The magneto fires the spark at a different time from old to new, even if using the same flywheel. Something magical is happening in the magneto.It's just a pickup coil, no electronics in it. You can tell that by just looking at it. I've never cut into one. I do know the older HS 142f's were faster than these newer ones. Exactly when is a good guess, maybe when they were EPA approved.
That would be ungoverned vs governed. If you still have the old engine scavenge the flywheel and magneto to get 30 mph backI could swear back in 08 I had a 142F FD setup with 1-1/8th roller and I could go 30mph. With these newer ones I top out at 22mph with the exact same setup.