Rough running like a miss after annual

Wow, it's hard to imagine how it got like that!  I'd be pretty unhappy with whoever did that work.  Did he do a carb balance for you?

I assume you are waiting on hose and not "hoes".  ?

Can't it be both??

The pic is of the middle of the hose. I cut the hose in half for easy disassembly of the tube. 

He is a "rotax authorized"mechanic too.

I want to use gates barricade hose but they don't have 7/16 Wich would equal the 11 mm that rotax sells. 

Think a 3/8 will work since the ID of the balance tube is 3/8?

This is why using aftermarket parts or trying to re-invent the wheel is not always a good idea. Why didn't someone just buy the Rotax hose for that part? Just use the Rotax 66mm hose that was designed and proper size for the balance tube and no issue. Over clamping hose can cause hose deterioration and lose hose pieces too. From the update picture I see the carb socket fixation screw for the clamp is lose, but from the picture looks like other hose choices and install aren't quite right. Be good to see an upper engine picture and side picture.

Any advice would be most helpful.

Couple more