This is a ripoff of the ST 29 of the time. One was tested in Aeromodeller, and performed abysmally, - power equal to a typical .15.
However, I had one of these, quality not very good. But I ran it on c/case pressure and a big venturi, it proved much better than that. I had it in a Nobler, and it took it quite o.k.
My engine was very soft compression, I made a special priming mix of 50/25/25, castor/nitro/methanol. With this, no problems. Very noisy.
I've no doubt the Russkie team engines were much better prepared.
Yours is a later model with a different c/case casting, and I think the quality may have improved.
Check it out for revs. on the bench.