Taking off in I-153 Chaika

[jezprior]

Hello,

I'm really struggling in taking off in the I-153 on the standard runways. I warm the engine up, move gradually to 50% or so throttle and then always end up veering left off the runway before I get anywhere near enough speed to take off. That's regardless of full rudder / ailerons / combinations thereof and I can't seem to lock the tailwheel. This happens even if I aim right before taxiing - it just means I careen off the runway a little later. I manage to eventually get in the air but only after bouncing over grass verges etc.

Help?