Hi guys, its been a while since ive been on here, i still lurk in the shadows but haven't had anything to ask since i got a honda

I have this mtd that i got going this morning (works well as you can see the trail of wet grass behind it in the photo) but cant work out the cutting height control, there is a big knob that is extremely difficult to turn but its not working anyway.
I cant see anything underneath dur to the design of the plastic base and the self propulsion mechanism.
Any ideas what i can do to get it working?
![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2016/09/full-2590-30138-rps20160918_164633.jpg)
Cheers, Emmo