Our red 205 suffers from fuel surge the same, so we make sure it has over half a tank for each stage (read as too lazy to fit a swirl pot)
Can i ask where you got the grA system from and how much it was please? i have a 2 inch magnex system on mine as thats what was on it when i bought it and was looking at making a 2.5in system in the near future....
From France its a GroupA item.
PM and will give you the details.