I have a BME that is acting up, and wanted to know if anyone has encountered the same problem.

Crank the engine, run it up. All is well. pull it back to idle. Let it set for a while. Sometimes, you don't have to wait, it starts to slow down. Open the throttle (yes, I verified that the throttle actually opens) and nothing happens. it just sits there, barely able to idle, like it loaded up or something. after a long pause (~5 sec) it accelerates like it should. Sometimes it will not spin up, but rather just slow down to death. It will run all day on full throttle.

I have adjusted the low speed screw way in, and way out. No change. Got any ideas?

lean to me or trash is hung up in the low end section of the carb, I don't know how far out you meen by way out but I would start the low needle at about two turns out and go from there. Good luck.

Sounds like the timing is not advanced enough. I recently adapted a DA single ignition to an RCS180. The timing was too retarded and it would sit there and just barely run over until somehow it would get enough rpm to trigger the DA ignitions advance curve, then it would take off and run great. I finally got the timing set about right and it ran fine after that. On a couple of occasions at half throttle it was still at idle rpm, and a few times it would just slow down and die, similar to what you are experiencing.

It could also be trash in the carburetor, but this would tend to make the engine just sag and instantly die when the throttle was opened, NOT continue running then catching itself, or slowly slowing down till it stopped.

I'd advise calling Keith at BME for a final analysis.