1933 V8: Troubleshooting...suggestions welcome

[torpedo]

Dear Barners,


Most of the time I try to figure out by myself when I face problems but on this one...


Some background: stock 1933 221ci - 6V positive ground - Stromberg 97 - stock dizzy (supplied by ThirdGen - less than 1000 miles on it).

https://www.transferxl.com/download/08vzcSq5t3KcNC


If you can't access the video on link above, the symptoms are that engine power is not coming when going full throttle. Above certain RPM it roars but without delivering power, just as if there was a limiter...



Troubleshooting done so far:
1. Replaced fuel filter > problem still there
2. Carburetor inspected, cleaned, checked power jet OK

At this stage the fuel supply issue was eliminated.


3. Played with dizzy adjustments like vacuum advance nut or ignition timing. This was probably a mistake because a. ThirdGen supplies them "ready and good to go" b. it's been working before without a miss c. I do not have the machine to setup dizzy.
4. Decided to swap dizzy with an identical unit (backup) also supplied by Michael. Problem still there.
5. I have good spark at coil

Thanks in advance for your suggestions/opinions