Runs in Clementi's Sonatina Op. 36 no. 3 (can't play in legato!!!)

[sachmaninoff]

Hi!

I'm playing Clementi's Sonatina op. 36 no. 3 rn, and I can play all the other things of that piece very easily but just can't play those (especially c major, bar 2 and g major in bar 16->) scale runs in legato. I've been struggling with these for a while, but I just cannot find the solution.

I can play very fast runs (almost clearly) in Kuhlau's Sonatina op. 20 no. 1, but I can't play Clementi scales in a middle speed (I can play them fast easily but not in regular tempo). I think the problem is in that part when I cross the 3rd finger with my thumb (c, d, e, HERE, f, g...). What should I do???

Thanks for answerings in advance!!!