Yeah I had a similar sound on my 150 Yammie not long out of the box and after a bit of process of elimination including the ram bushes which were all good but in my case it turned out to be the engines main horizontal pivot tube or whatever its called. Has a big nyloc nut either side of the engine where the steering mounts etc. It was overly tight causing the binding and creaking sound when tilting. I just backed off the nut a quarter of a turn and fixed it instantly.
Good luck with yours..