Just put a YS 110S in my Venus replacing the OS 120 it was originally powered with. No issues with the OS, I just prefer YS'.

I moved the tank back to the CG and thanks to it's lower weight, removed the 2 oz. of lead needed in the tail to balance out the heavier OS engine. I haven't flown it yet though I did run it on a saftey stand. This thing is a BEAST!

I'll post pictures of the install later.