Regarding your TR250 crankcase ventilation system, particularly the photo of the air cleaner (2008 post) showing a hose from the air cleaner to the emissions valve, you state the hole is restricted.. Would you recall the size of the hole? I am installing the same set up on my triple S.U. carbureted TR6 engine. I currently have the hose from the emissions valve attached to the port on the center carb (other two carb ports are capped) but not sure if as good as to the air cleaner. I am experiencing a bit of surging on mild acceleration, but not sure of the cause. Perhaps attaching the hose to a barb on the airbag (Richard Good title SU air box) may be better. Thank you!
Here's a photo showing the orifice; 1/8" IIRC. I think you reached me on the TRIUMPH EXPERIENCE site, right? I'm not very active on these forums lately as TRs are celebratory for me, and that mood is in a state of suspension for now.