If BMC had half the engineering experience of Otokar she'd put another engine on it by now.
They actually have some MTU engines in storage,it was told for a few times the production would start with the spare engines procured for prototypes but then they have probably failed to install it too.
Because they did only receive Technical packages from SSB,not the production packages which includes production details and plans. Otokar was obliged to share technical documents with SSB as a part of prototype production program but was not for production packages.
BMC might have tried several times to pay for the technical packages but Otokar had given none, there might have been some deal recently which Koc might be granted with some projects in return of sharing production plans with BMC.
The only proof of how they lack production plans is they couldn't make an actual turret for LeoTay but instead made a make-up on another turret with welds and joints.