Look,, I'm no expert and I don't claim to be. But,, I own a 160FX myself and have gone the green mile messing with all the after market fixes. Bisson muffler does not seem to produce as much tank pressure as the stock. TRUE. But in most cases who can run these giant stock mufflers on their planes ? (Without hacking everything to shreads.)
The point about rich low end and lean high speed needle settings makes good sense. I was deadsticking one day and tried the leaner low-end setting and did not flameout once. That was with a Perry VP30, stock muffler and 18x6W APC.

Again,,, no 2stroke guru here but I'll tell you what seemed to help me and maybe it will for you too.

Changed from the OS-8 and OS-F glow plug to the OS-A5. The A-5 instantly got rid of the mid range knocking and made for a smoother mid throttle flight.
Set the low-end by pinch test and transistion rate. Also you want it to back-flip easily so don't go too lean.
Set the high speed slightly rich to keep the engine cool. It will smoke alot but this seems to be the norm on the 160.
Now for the pump and extra junk. I tried all the pumps. Just makes the problems worse unless your wanting to set the tank on the CG. The larger fuel line theory is bunk too. I think one of the earlier posts from ? made the comment about too much fuel instead of not enough. I think that is the problem here because if it was a lack of fuel everyone would be deadsticking while at full throttle and most are not. It mainly happens at half throttle or while throttling back from full.

Cline Demand Regulator ! Ok,,, I know I woul;d read these posts about them and think,,, "Geez,, $60.00 ,, what else will they try to rip me for ?" But,,,, I inverted a Saito150 on a warbird recently. I must admit,,, they really work well.
Now with that in mind,,, does anyone here have an OS160FX with a cline and Bisson muffler that's still giving them trouble ?
I haven't ordered another Cline for my 160 yet. The big bore OS has totalled a large Edge 540T for me and almost did the same to a FW190 by deadsticking at the worst time. But if the Cline helps the 160 it might be worth looking into Acam37.