Hello all- thanks for looking at this!!
First of all, I got this years ago- Boeing discard. No labels to identify- I think is a 60 series, has Monotrol transmission. Chevy 4 cylinder, propane. Engine runs good, hydraulics operate no problem- will lift whatever I demand of it, engine will rev up properly. The problem is that it is super sluggish in both forward and reverse. It will barely go up the slightest grade; if I have a 3/8" rise in a concrete slab joint I have to get a run at it... Wondering if anyone might shed some light on where the problem might be... ?

Again-thanks for looking at this!!