I have the same plane with the same engine& prop ( I have 5 OS 52 and I run APC 12x6 on all of them) ( see my pic of Valley Forge Christmas) I am flying it on skis at this time. If you got that plane up as quickly as you say with that combination and it balances on the spar. It was forced into the air to quickly bottom line period. I have over 200 flights on mine I have never had a problem with it doing that. I always let the tail come up and run on the ground for a bit before I rotate. Is a wonderful plane. Can do almost anything with it.
The DiBo