How in this world does the Scram X9 rear derailleur go? I can't seem to get it right. I believe I have the stop pin positioned corrected per owners manual but the cage is clear folded up against the cassette. I will try to attach pics.
The chain line looks terrible and currently is rubbing hard against the chain stays. I know this isn't right.

Advice please? I have the idler roller placed under the seat with the power chain under and the return chain over. Looks right but the chain looks like a snake from the idler to the cassette.

Yikes, what gives.

What are you trying to achieve, starting with the mid chain idler pulley?

Or put simply, why don't you use the normal derailleur chain routing where the lower loop goes directly from the bottom of the chainring to the RD cage?

It looks like there are a few things going on. First from photo 5 i think your der hanger is bent. The cage doesn't look like it's coplanar with the cogs. Then the der rotation limit screw should be turned in so the upper pulley clears the chain stays. The chain looks to be properly routed through the cage and around the cassette. Not sure what you mean by "like a snake", the cassette to pulley chain run looks right to me from what i can see. Does the chain rub on something? Well it does rub on the outside of the chainstay on the chain's return stretch, pulley to cage. Try putting the chain inside the stay. How did this happen? Did you install a chain? Best understanding and suggestions can only come from a complete description of previous history. Andy.

Recumbents my guess: the Bottom, slack side of the chain goes over the roller, to keep it from dangling ..

the taught side that is the top, where your power input goes is a straight shot from rear to front.

though with the separator maybe both go over ... are the rollers 2 side by side? able to turn on opposite directions?

got the owners manual?, ask the builder if theres a PDF to send.

Three replies and three possible answers. This is why it's so hard to give correct advice without the bike being in front of one. Fietsbob sees a chain routing i don't. Both he and Francis hasn't mentioned the return run of chain rubbing on the stay. I'm unsure of how the tension run should be routed WRT the pulley. And the angles of the photos make me think the der is not straight but...

Perhaps another bunch of photos taken from other vantages will provide more info. Or just experiment with the chain's path and see what works best in all the cogs. Andy.

I didn't get into any specifics because there wasn't a place to start. Without knowing why there was a pulley in the first place, there was no point in addressing the specific routing problems.

However, as long as we're just expected to throw stuff against the wall, is it possible the idler pulley is supposed to mount in a different place, like the lower stay?

It might help to see the front half of the bike. If you really need an idler pulley, it probably needs to be down a lot lower.

Look up some other recumbents to see how they do it.

From other posts about this newly-acquired Sun EZ Speedster AX, OP has shared that there may be a problem with the RD hanger. From other pics of this Sun model, it can be seen that an idler is used that places the power side chain (upper) under the idler and the return side chain (lower) over the idler. It's a dual idler, according to the pics.

I can't tell what's going on with this bike: more pics needed, especially from the drive side, from the crankset to the rear wheel.

I've included a couple more pics to help you visualize the drive line. I do have the power chain under the idler pulley and the return chain on top of the idler pulley. Dual idler would be correct. Derailleur hanger/bracket is actually fine. The cage bolted up to if just fine too. When you view the return chain pic, see how it is rubbing hard against the chain stay. There are no scratches or rub points on the stay now so I doubt I have it right. Allowed to rub, it surely would wear right through the stay itself.bi understand cross chaining, but I'm on the middle ring up front and in the middle of the cassette. This bike had been ridden just before I acquired it. So I've mis assembled it somehow.

The return run of the chain should be inside of the stay.

The chain needs to be inside the chainstay as it goes from the bottom of the derailleur pulley/cage up to the idler. (As previously suggested). You can see the chain routing in this pic.
If you search, you might be able to find some better images of this model bike.

Well, I thought that too. But how did the previous owner have the chain on the outside of the stay? Surely he didn't break the chain and reassemble it as it is now? Guess I've got some work to do now. Thanks for all the tips. I just thought I was losing my mind.

Um, have you considered asking the previous owner how they had it set up? They might even have photos.

I broke the chain tonight using a chain tool, moved the chain to the inside of the chain stay, installed a quick link and I am good to go. Ran through all the gears and only needed minor adjustments. Yippee.