Not necessarily.

Foaming is hard to find and cure because it can vary:
1. with engine RPM.
2. with the amount of fuel in the tank.
3. with the attitude of the airplane.
4. with the addition or removal of a structural member.
5. by simply holding the airplane rather than flying.

A loose fitting tank protected by latex foam rubber is the best insurance against foaming.

The upside is that you may get very good at dead stick landings.

Bill

For what it is worth I have been working on an engine problem that started with foaming for about two weeks. Along the way three other engine problems were found and are now fixed. A smaller tank and liberal foam was used but the foaming problem still exists. The bubbles are much bigger than the pinhead size bubbles initially observed. Just cut a structural member for more clearance. Really hated to do that. The original 4-stroke engine did not have a problem with the original tank.