Sorry for the delay, Denise. If you are saying the trifold sofa is uneven when unfolded, then my only recommendation is a different brand or type of tri-fold sofa bed. I've never seen an even sofa-bed in this style, but they likely exist somewhere. I went the other direction with a CouchBed - a hinging, dual configuration, dense futon-like sofa, that's a better day bed than couch. It's on a retractable platform for the perfect height and depth in either configuration. We replaced the original trifold sofa with this and saved space and weight. It's a very comfy bed. Been sleeping like a rock on that baby! Requires a bit more work to convert than the trifold, so that's a compromise. Best of luck on your solution.

To lift the head, you have to remove the frame from the sides and then raise and and reattach the frame to be level. It’s really quite easy. I have done this to 2 Thomas Payne Trifold sofas and they are both completely fine now.

If I remember correctly, they were two inch lag screws, probably about #14 in size - you can see where they attach from the metal frame to the side pieces at about the 40 second mark of the vid.

It was bad fuel from a container I thought was fresh fuel. But it did gum up the carb, so that got cleaned. Runs great now!