3-Point Hitch Slowing Yanmar YM1510D 3pl rise speed to use as a crane

[13gef13]

I have the above and want to use the 3pl as a crane, which I have made the boom etc., to build a shed/barn. The speed of the lift makes this very hard to control. I have the parts book/service manual for it but there is a control near the right hand rear wheel which is shown in the manual but makes no mention of what its for. There is a control near the seat, in the middle which controls the lowering speed but this doesn't seem to affect the raise speed. Does anyone know what the other control, near the rear wheel is for, I would hate to bugger something up through ignorance.
Thanks, Geoff

 

[Barry 1]

The one on the right is the rate of drop valve.The front one is for locking the three point up and should be unscrewed all the way out most of the time.The only way to slow the lift,is to idle way down,and it's still too fast.